@ehBeth,
Yes, that's the direction I've gone too. I used to really dislike spicy foods (and my dad really liked spicy foods, so that was a frequent struggle). Now I like them a lot.
I don't think it was a situation where he was right all along -- I think the age difference really makes a difference with spiciness, just how sensitive your taste buds are.
Sozlet likes spicy foods more now than she did when she was littler, but her tolerance is still far lower than mine or E.G.'s (and I don't push it).
But tastes just change in general too. I see I've already quoted it here a couple of times, but the thing about people often needing to try a new food 10-15 times really made an impression on me. I definitely saw that with sozlet when she was little -- when she didn't like something we'd just kinda say "OK" and move on, and then introduce it again later. And many of the things that got a nose-wrinkle initially became favorites several tries down the line.
Right now she has zero permanent dislikes. She's big on novelty, though, which means various fruits (especially) rotate in and out of her favored list. Bananas do a lot of rotating. She loves them for a while and then won't touch them for a while.