Is there a band you disliked when you were younger and started liking much later?
For me it has to be The Cure. I really disliked them in high school somehow (I guess the silly looks of their fans played a part), then I started thinking they were okay when I was in college, and now, decades later, I'm blown away by how amazing they are, both the old stuff and the new one. And Robert Smith is also one of the good guys.