I realized a while back I do this. If someone's ask me if I know or have heard of someone, even if I don't, I'll squint and go "Hmm, ya, I think I heard the name".

I never have, it's more to keep the conversation going since I expect them to tell me, but it did strike me as a petty and silly thing to do when I realized I was doing it. Just can't admit to not being knowledgeable, gotta just stay vague about it and pretend. Bad habit.