I'm 35 and have relatively recently gone out with a 24 year old, a 20 year old, a 27 year old, a 30 year old (and possibly a couple I have forgotten.
When I see many women my own age, I think they look old or out of shape, so a lot of it is physical, of course. Most people who don't know me think I'm about 27-28, and I go to the gym about 6 days a week, so physically i'm not totally surprised to date younger women, but it is a little harder for me to imagine being in a relationship with a much younger girl, although hooking up is fun. I find that a lot of 20ish girls, and girls my age or more, are far more flirtatious with me than their 25-30 year older counterparts, and they seem fairly comfortable going beyond flirting, as well. odd...