Is it wrong if I prefer to hang out with people who are 20-30 years older than me?

Nothing wrong with that, for you. If I wanted to do that, I'd have to go to the cemetery.

Most people find older, mature people to be less obnoxious than teenagers, so this isn't all that bizarre. But at the same time you'll need to find ways to cope with being around your own age cohort because until you're finished with education you'll be surrounded by kids your own age. 

YOU are one in a million. I believe much more rational then the normal. Most young people have no clue what life is about, they change daily. VERY unstable, this is the reason so many young people choose the wrong partner. I say continue YOUR way, you will learn much more about life, the way things go, opportunities may open for you others do not have and may even find a much better match who can truly be the one for you EVERYDAY.

My girl friend just turned 30 years old, half my age she has been with me 5 years now. When I met her family in another country they Thanked me for the influence I had on their daughter. She has grown into a well rounded, well put together woman. ABSOLUTELY stunning !

As they say Sweety, sometimes when you follow the Masses, the "M" is silent.

It's fine. A lot of people, including some children, prefer adult company. If you're not finding shared interests with people your own age then obviously your turn to people NOT your own age for companionship.