It is an unreplenishable loss. He was like the sun and we all revolved around him, knowing that he is there and whenever we need some advice or want to clarify an idea we can approach him. During my PhD days (1993-1998), I never found him tired. Even if we approached him during the late night tea at the east canteen and wanted to discuss our findings or general issues in science, he displayed full enthusiasm. I have learnt so many things from him including how to give a good talk. I am blessed that I am also a part of the scientific culture that Obaid has created. Mrinal.