I'm one of the lucky ones, as I grew out of my teenage years my brain changed and seizures stopped. You never stop looking over your should or thinking about it though, not at all.
One theory a doctor posed to me for why this could be happening (he'd seen it before), was simply down to neural pathways getting more set as you get older - the analogy he used was that a seizure is sort of like your brain short circuiting, so if it's less plastic that may make you less prone.
It's just ridiculous how adaptable the human brain is, I love reading about this stuff.