What happened to me on my 18th birthday?

I was wondering what happened to me only 18th birthday? I remember it being uneventful since I don't really celebrate my birthday so I don't remember anything special happening? All of a sudden I was not disgusting to the 18± crowd but I but as far as I can tell I looked and felt the same. I also apparently missed something during this evolution because I was supposed to think anyone 17 and below was nasty but I still found them attractive.

So what happened to me and what was supposed to happen to me on my 18th birthday please explain.