(You will remain silently in my heart ... always!) - Rabindranath Tagore
Dear Sir, I will be indebted to you for life.
Even as I write these words, I cannot reconcile myself to the finality of them. You have left us, Sir, and the void you've left behind feels impossibly vast. This grief is profoundly personal—you were not just my mentor but a guiding light, someone who shaped the very person I am today. But this loss extends far beyond my own heart. India has lost one of its brightest minds in NLP and AI, a visionary who built bridges between fundamentals of language, cognition and modern technology, between tradition and innovation. While there are now many great minds taking your legacy forward, we know you had the greatest share in these contributions, putting Indian NLP firmly on the global stage.
I probably never said this to you directly, Sir, and that realization haunts me now: I am immensely proud to have been your student. Proud beyond words. Grateful to the Almighty for placing me in your orbit, for allowing me to learn not just from your brilliant mind but from your generous heart. I will always be your student, Sir. Always. That bond will never fade—it only deepens with absence.
You left us too soon. Far, far too soon.
Where I stand today-- the foundation of it all is YOU. Every paper I write, every problem I solve, every moment of clarity in my research, I trace back to your teachings, your patience, your unwavering belief in me even when I doubted myself. You didn't just teach me natural language processing or artificial intelligence; you taught me how to think, how to question, how to persist. You taught me that excellence isn't a destination but a discipline. You taught me to wake up every day with a sense of greater purpose and be relentless towards achieving it, but in a disciplined fashion.
I remember how you pushed me—sometimes gently, sometimes firmly—to aim for the top-tier conferences and journals. I still recall my second year when I wasn't publishing as much as my peers—frustration crept in. I used to tell you this, but you always insisted that my research should be visible at the highest level. And one day after class when I nagged you about one journal which was not up to your standard, you scolded me for the first time "You should leave PhD and go back, Tirthankar! You can't do it, you are giving up so quickly!" I was upset and felt low at that time but now I know the value of that "strictness". At the time, those targets seemed insurmountable. But you saw something in me that I hadn't yet seen in myself. I was still considering myself fortunate to be at an IIT and that too under you; it was overwhelming for me. Those publications became the foundation of my career, the building blocks of my research acumen. Every acceptance letter, every citation, carries your fingerprints, Sir.
But our relationship transcended the boundaries of academia.
I still remember, Sir, when you volunteered to host my wedding reception at the Director's Bungalow at IIT Patna. You were the Director—the Director of an institute of international repute—and yet you opened your home to celebrate one of the most important days of my life. That wasn't protocol. That wasn't duty. That was love. That was you seeing me not as a student under your supervision but as someone whose happiness mattered to you.
Aparna Madam was equally warm, equally gracious. The connection between our families deepened when my wife (Poulami) joined as a Computer Science teacher at the school (Foundation Academy) where Madam was Director. We visited your home multiple times, and each visit was marked by your incredible hospitality. Despite your positions, despite your stature, you both treated us with such genuine care. There was never a hint of formality that creates distance—only the warmth that builds family. Poulami recalls you telling her once in your bungalow, even as you were busy discussing a paper with me—'পৌলমী, dinner করে যেও কিন্তু! আর কিছু না খেলে 'মাছ' খেয়ে যেও। পাটনা থেকে ভাল মাছ আনিয়েছি।' (Poulami, don't leave without having dinner. Do have the fish. Just had it brought fresh from Patna).
The memories flood back now, each one a bittersweet treasure. Those cricket and badminton matches after office—do you remember, Sir? The way we'd all gather, exhausted from a day's work, but finding energy in the joy of play? Those dinners that stretched late into the night, conversations meandering from research to life to everything in between. Those moments taught me that brilliance doesn't preclude playfulness, that even giants need to unwind, that some of the best ideas emerge when we're not formally brainstorming but simply being together.
And those late-night research discussions! Sir, I know how demanding your schedule was. As Director, your time was pulled in a thousand directions. Yet somehow, somehow, you carved out hours for me. One-on-one sessions where you'd lean in, fully present, helping me untangle knotted ideas, showing me new pathways through seemingly impossible problems. You made me feel like I mattered, like my research mattered. Do you know how rare that is? How many students wish for even a fraction of the attention you gave me? I recall waiting for you in the Director's office, catching you in the corridors, even walking with you to your car on your way home after the day's work—seeking your guidance on so many things, not just research.
You were there during my darkest moments too. The COVID-19 lockdown period—when the world stopped moving and motivation evaporated—I was drowning in that stagnation. Nothing seemed to progress. Hope felt like a foreign concept. I lost my internship at Harvard and my PostDoc opportunity at Stanford as funding dried up and travel became impossible. But you became more than my research supervisor; you became my life coach. You didn't just give me technical guidance; you gave me reasons to keep going. You reminded me of my purpose, helped me see beyond the immediate paralysis. Those conversations, Sir, they saved me professionally and personally. Thank you! Thank you for everything! Who will guide me now?
And then there was that beautiful moment at Research Scholar's Day in IIT Patna—receiving the Best Talk Award from your hands. I can still see your smile, Sir, the happiness in your eyes. That award sits in my office now, but what I carry in my heart is the memory of your approval, your acknowledgment that I was on the right path. And I still remember when you said during my first USA conference trip, "Tirthankar, I am little jealous of what you are feeling now, the first foreign trip is always exciting, a different feeling far from your homeland, and you make crazy little mistakes that you remember throughout your life".
Do you remember our chorus performance of "একলা চলো রে" (Tagore's anthem about persevering even when you must walk alone) in the International Mother Language Day on February 21st, 2016? I don't think I have the recording of that now, but every moment standing on the dais and singing with you is vividly etched in my memory (Sudipta and Sriparna madam were there too). And now I have to literally walk without you, live those words!
The small details define us as much as the grand moments. You loved chowmein, Sir. Such a simple thing, but I remember it. I made sure we had that dish whenever we were together—at dinners, at celebrations, at casual gatherings. It was my small way of showing care, of acknowledging that you were more than a towering intellect; you were a person who enjoyed life's simple pleasures. I hope you knew that those gestures came from love and gratitude.
I remember you asking me about my daughter, Sir, after she was born; I had graduated by then. Your face lit up when I told you her name—Sharanya, the other name of Mother Durga, meaning "one who gives refuge to others." You were so pleased with the depth of meaning we had chosen. "Beautiful, Tirthankar," you said. "She will live up to that name."
I regret deeply, Sir, that I could not bring Sharanya to you to receive your blessings. That opportunity is lost forever now, and it haunts me. She will never feel your hand on her head, never hear your voice speaking words of wisdom over her life.
But I promise you this: Sharanya will grow up knowing you. She will hear your stories. She will learn the values you taught me. Every lesson you imparted to me, I will pass on to her. She will know that her father became who he is because of a great teacher who believed in him. And perhaps, in some small way, she will give refuge to others—just as her name promises, just as you gave refuge to so many of us who sought your guidance.
You will live on through her too, Sir. Through the next generation.
Sir, I am devastated beyond words. I cannot believe you are no more. I have been constantly complaining to God since you left ... God, this person should have been in this world much more to nurture many more young minds; you took him too soon! too soon!
This pain is unlike anything I've known. I have lost loved ones before—we all have—but your passing has shattered me in ways I never imagined possible. Perhaps it's because somewhere deep in my subconscious, I had placed you beyond mortality. You were my constant, my North Star. The thought of a world without you simply never entered my mind. How could it? You were eternal to me—like a force of nature, like God himself. How can something happen to god?
I miss you in ways I cannot fully articulate. I miss your voice on the phone, the way you'd say "Hyaan Tirthankar" with that particular inflection when you were about to share something important. I miss your wisdom, your laugh, your presence that could fill a room. I miss knowing that you're there—just a phone call away—ready to guide me when I stumble, ready to celebrate when I succeed.
And there's regret too—sharp, unrelenting, suffocating. I missed wishing you on Teacher's Day this year; which I never missed so far. Life became overwhelming with personal and work-related problems, and I let that connection slip for just a moment. Just one moment. I didn't know, Sir. How could I have known that our time was running out? That there would be no next Teacher's Day, no next phone call, no next chance to say what my heart held?
If I had known, I would have told you every single day: You are the best teacher I could have ever hoped for. You shaped my life in ways both profound and subtle. You made me believe in myself when I had forgotten how. You saw potential in me that I couldn't see. You built me, Sir. And now I must stand on that foundation you built—without you here to see it.
But perhaps you knew, Sir. Perhaps you always knew.
You will live on through me and through every student whose life you transformed. Your legacy isn't just in the papers published or the algorithms developed—it's in the hearts you touched, the minds you opened, the futures you made possible.
India has lost a pioneering researcher, a visionary leader, an institution-builder. I am no one to comment on what a towering academician you were—the world knows it, acknowledges it, celebrates it.
But I? I have lost a mentor, a guide, a friend, my role model. You were the perfect definition of a polymath. I was always in awe of how you managed so many different roles—as Director, as Professor, as the first person from India to be the president of ACL (the highest body of Computational Linguistics/NLP), as research supervisor to so many students, leading countless international, national committees and projects, your passion for Indian classical music and your singing performances, your writing, and so much more! The list is endless. And you did it all with such dedication, such excellence, such grace.
Rest in peace, Sir.
Your teachings will guide me. Your values will anchor me. Your belief in me will propel me forward. And wherever you are now, I hope you know: I am forever your student, forever grateful, forever proud to have walked even a small part of my journey with you.
You left us too soon, Sir. But you left us better than you found us.
Thank you for everything. I will meet you sometime on the other side and listen to you again.
🙏
— Tirthankar and Poulami
আমি বহু বাসনায় প্রাণপণে চাই, বঞ্চিত করে বাঁচালে মোরে।
এ কৃপা কঠোর সঞ্চিত মোর জীবন ভ'রে ॥
না চাহিতে মোরে যা করেছ দান-- আকাশ আলোক তনু মন প্রাণ,
দিনে দিনে তুমি নিতেছ আমায় সে মহা দানেরই যোগ্য ক'রে
অতি-ইচ্ছার সঙ্কট হতে বাঁচায়ে মোরে ॥
(I desperately wanted many things, but You saved me by denying them. This harsh grace has filled my life. What You gave without my asking—sky, light, body, mind, life—day by day You are making me worthy of that great gift, saving me from the crisis of excessive desires.) - Rabindranath Tagore (prayer 🙏 by Sahana Bajpaie https://www.youtube.com/watch?v=sG_QrfxoQrY)