In terms of large age gaps, definitely older people. Obviously, the closer we get in the age, the more it doesn't matter if someone is younger. Maybe up to 6 years younger is fine.
Returning to college as 27 years old a few years back really opened my eyes. I really thought beforehand that I still was not much different from an 18 year old, even at that age... But no (and, really, it was a surprise, because I was at a different university a few years earlier, and the freshmen then didn't give me this vibe). The 18-20 year olds there were like children to me. Lol. It's not as big of a deal as I make it. I still made plenty of acquaintances and some friends there that are like 8-9 years younger than me, but that's probably because I can be pretty adaptable.
Returning to college as 27 years old a few years back really opened my eyes. I really thought beforehand that I still was not much different from an 18 year old, even at that age... But no (and, really, it was a surprise, because I was at a different university a few years earlier, and the freshmen then didn't give me this vibe). The 18-20 year olds there were like children to me. Lol. It's not as big of a deal as I make it. I still made plenty of acquaintances and some friends there that are like 8-9 years younger than me, but that's probably because I can be pretty adaptable.