QUOTE(Liege @ Mar 22 2012, 06:20 PM)
It all makes perfect sense.
Except for why someone would want to remain a prepubescent boy forever...
Alternatively, Ash has a severe growth disorder similar to what Konata's mom had. As a result of this disorder, he doesn't age as fast as he should; although he's getting into his late teens, he's physically still only 11 or 12. This may have been something he inherited from his mom, who is repeatedly shown as looking a lot younger and a lot more attractive (up to and including winning a beauty pageant against girls half her age) than she should be given how old she likely is.
As far as Ash is concerned, his life is a living nightmare. On one hand, he'd love to have a girlfriend and a reasonably normal existence; this is why his first act upon going some place is to find the cutest girl who's presently available and convince her to travel with him. On the other hand, he's afraid that if they stay together for too long, his condition will manifest itself, resulting in ever-increasing awkwardness as a teenage, and later adult, woman is keeping company with what appears to be a much younger man. Given this, Ash inevitably chickens out and ditches his latest squeeze, even leaving the continent to justify doing so. The only reason why he stayed with Brock for so long was because Brock, given his (limited) degree of medical knowledge, understood Ash's situation and wasn't bothered by it.
On the other hand, the mon of the series don't particularly care how young he looks. Hence why Ash is so close with them - he can love them without the public asking questions. In exchange, his mon have picked up on his self-doubts and so make it a point to love him back once they've gotten to know him better. That's how it is that his mon, who are often barely even trained, can so frequently squash much more competent warriors. In that sense, Ash lives to battle not because he truly wants to be the champion, but because it gives him an excuse to hang out with something
that isn't embarrassed by him. What's more, if he becomes the champion, that'll give him all the opportunity he needs to go public with his condition without fear of a public backlash: he's the champ, and so who can second-guess him then?
Until then, Ash keeps traveling and keeps leaving an ever-increasing string of girls (Misty, Duplica, Dawn, May, Iris,...) who would gladly be his wife if he'd only man up and tell them the truth.