Demi Lovato is an example I can think of. They came out with a great song - 29 - about their relationship with what's his name that was on that 70s show. He was 29 at the time, demi was 17 when the relationship started. At the time, they were very vocal about it being super healthy, wonderful, and all that. After getting sober, looking back, and looking at people those ages, they realized how much societal expectations and the attention received actually impacted what they thought they wanted at the time.
I don't follow much celebrity news though, so that's the only one I've got