It depends on the people involved, I am 25 I personally couldn't be with anyone younger than 18 or older than 36, those are the ages I feel comfortable with. I have been lectured before by 40+ guys saying age shouldn't be a factor and I am being closed minded etc.
And while for some age isn't a factor, for other it is, I am still experiencing new things finding out what I like, I rather be around people who are also doing the same not someone who has already done that settled down and figure out everything they want and don't want and limiting me. And I while that is more personality associated with older than the actual age, there is also comfort I just don't feel comfortable in intimate settings with someone who could be my father.
I have chatted with some cool older guys who and some real jerks who lectured me and talked down to me like I was a child, which is funny since I have one of the older personalities, I don't like to go clubbing, I am not a party guy, I enjoy dry wit and satire more than cheap comedy. Lecturing others on what to do and what not to do how to feel etc because you feel more wise since one is older is one of the traits I have experienced often in my interactions with big age gaps which is why I no longer try and now I get lectured for being closed minded since I gave up on trying, it seems no matter what people want to lecture me with things to do with age difference.
While some might want to bridge the gap, often they still treat the other with attitudes for their age which can cause friction, like in my case old talking down to young, and young getting frustrated with being treating childlike, but I could also see young trying to get old to be more spontaneous and wild, and older get frustrated with the youth.