Jan. 5: When Sundar Pichai was asked today about his favourite professor at IIT Kharagpur, he chose two: "Professor Roy and professor Indranil Manna, who is now at IIT Kanpur."

"Prof Roy" is Sanat Kumar Roy, a retired professor of metallurgical and materials engineering who taught Pichai when he was an undergraduate student of the batch of 1993. He spoke to Metro about meeting one of his favourite students, now the Google CEO, outside the classroom after two decades.

He was seated next to me and looking at me shyly, exactly like he used to 25 years ago from a corner bench at the front of my class. It was almost difficult to believe. Here was a man who heads a company worth several hundred billion dollars, someone who hobnobs with the who's who of the world, but who had still apparently failed to shake off all vestiges of the shyness that he was known for as an undergraduate student.

When we met, he recognised and greeted me with a namaskar. That was exactly why the director of IIT Kharagpur had invited me to the campus. I retired in 2015 but the director wanted me around so that Sundar could see at least one familiar face during his visit.

Sundar had too many things to do during today's visit, so we could speak for only a few minutes. He said I had aged, and I reminded him that I am over 70 . We clicked a few pictures.

I have been told that Sundar today referred to me as one of his two favourite teachers at IIT. I feel content when former students like Sundar appreciate my effort. He was a resident of Nehru Hall, where I too had stayed when I was a student from 1962 to 1967.

When Sundar wanted to leave for Stanford University for his master's, I wrote his recommendation letter. And I have done so for many other students. Many people ask me why I play a role in what they call "brain drain". But I believe brain drain is rubbish. Quality knows no boundary. Humankind benefits from what a brilliant mind creates. Sundar is a case in point.