My officemate is 34 and has expressed interest in young women who are just barely out of high school. I think it's disgusting too. He says it's because he wants kids and isn't likely to be able to have them with an older woman (divorced women with kids are off the table for him).

One of my grad school professors was 65 when his 40-year-old wife had a baby. I can't imagine going through that either.

Mostly, as someone said earlier, it's probably just an ego thing. Not to mention a sign of intense insecurity.