[refurb]

I had a professor in graduate school like that. He was probably 70 and did natural product chemistry.

Unlike the other professors who were hard asses because: 1) they were still making a name for themselves or 2) they dealt with it in grad school, so you should too, he was the friendliest, most curious person. You could be a 2nd year undergrad and if you asked an interesting question, he’d get genuinely excited about it.