At Cornell, at least among the students, Sagan seemed to have the reputation of being very full of himself. I don't know if it was true. I do remember a silly story about a fraternity getting mad for no reason because they assumed it was true.
Sagan's house overlooked the gorge, across from the fraternity. My freshman or sophomore year they invited him to dinner, and just got a call from his assistant, who had no idea the invitation was from his neighbor or even a Cornell fraternity, saying something like he wasn't available that week, but if they wanted to book him to speak she would try to arrange it.
The fraternity assumed Sagan was just living up to his reputation and would only have dinner with them if they paid him, so they painted a banner saying basically F . . . U, and then put on their roof so it faced his home. Turns out Sagan wasn't in Ithaca that semester.
As to being lucky to meet Asimov, I agree! It's funny though, I was just a kid, and while I'd read the Foundation books and a few others, I hadn't realized yet how exceptional he was. Maybe that's why he took the time to chat with me. Unlike the adults, I wasn't in awe of him. I just thought he was a cool guy who wrote entertaining stories and had a goofy beard.
Well, OK, that's still how I think of him