One adolescence is plenty, thank you.
I came out at 18 and I don’t really know any queer adults, but it seems to me that they haven’t fully been “living” while having such a big part of their life concealed. As much as I enjoyed high school and had a lot of fun and good memories, I wasn’t fully being myself. I still had to lie about my sexuality and I didn’t explore it at all during that time. So once you finally give yourself the freedom to do that, you might get a little carried away.
I’ve talked to many LGBT kids who come out and people who come out and are well-received feel like they can do anything once they do it. It’s empowering and it’s a huge burst of freedom. Some people take it too far, though.