Like a lot of people, I interact with lots of others in different age ranges; some are close to my own age, some are 5-15 years younger (or older), and some are even younger than that! I think it's good, to not just be friends (or friendly) with people your own age. Talking to someone else that is much younger or older gives you a new perspective into the world.
That being said, for the longest time (thank the Gods I stopped doing it!) I was only attracted to women much younger than me. When I was in my mid 30s, I only seemed to chase women who had barely passed the legal age to drink (21 here in the States). As I've gotten older, I thankfully outgrew that phase, and for two reasons.
The first being, that as a general rule, women that young aren't attracted to a middle-aged guy who has 3 kids and is divorced. They just want to have fun, and there's nothing wrong with that. For a lot of them, they have little to no real responsibilities and being who I am, I have tons of responsibilities. Again, not saying they are all like that, but a good portion of them are, and there's nothing wrong with exploring all that life has to offer when you are "young and dumb" as the saying goes.
The second reason I'm glad that I moved on past that phase is, it was difficult to relate to them on more than a few things. And that's where a relationship can truly break down. Sure, you can find them very attractive (and vice versa), and sure you may have great chemistry and be fantastic together in the sack. But, if those times you aren't making out or in bed are awkward and she doesn't get your jokes, and you don't get hers, the relationship will only be physical. And while there isn't anything wrong with that either, as you get older that type of relationship gets boring. You don't just want a lover, you want a companion.
So, there you have it. Now, obviously my perspective shapes how I view things, but for me, seeing a young woman I'm physically drawn to is always tempered by my knowledge that it will just be a temporary thing, and I'm content to wait for the real thing.