The breakdown by age is pretty stark:

http://www.nbcnews.com/storyline/brexit-...te-n598481

Basically people under 50 wanted to remain, especially millennials. They basically had this forced on them by a bunch of bitter, resentful old people, and will have to live with it long after the "Leave" voters are gone. Oversimplification, but a lot of truth to it...

Edit: Lest anyone be offended, I'm pretty close to qualifying as "old" in this case, and probably already do from a millennial's perspective. ;-)