I'm (23M) the "forgotten" friend in every one of my friend groups.

A common theme for me, especially since graduating high school 5 years ago, is that I'm always the forgotten friend in all of my friend groups. I don't really have any friends that when trying to do something, I'm the first they reach out to. It really hurts when I hear what a great time everyone had the night before and then get asked why I wasn't there and its 95% because I wasn't invited. The only person who ever had me first on their mind in my entire life is now my ex-girlfriend, so I don't really have anyone who actually wants me around. The only time I'm called on is if I can DD, otherwise, if I actually want to go out and enjoy myself and have a few beers, it's a hassle for everyone.

I'm aware the common factor here is me, but I can't figure out what or why I always seem to be forgotten about. I try to do my best to fit in, but I'm typically ignored or if I give my input on a topic I'm knowledgeable in, I usually get ridiculed. It's sounds toxic, but I'm quite shy at first and I hate to be a bother to people, so I typically can't talk to strangers.

I'm not really sure what I'm looking to get out of posting this, but I just needed to tell someone. Maybe give that one friend a little more attention, because maybe you're all he/she has.

TL;DR: It sucks being the black sheep friend in every social circle.