Hi,
By the time I was 19 I was playing with 40 year old guys. You can learn a lot very quickly. Not only do you learn new (to you) tunes, you learn how musicians work together and interact, both musically and personally, you learn what it takes to pull off a "professional" gig, you learn how to come prepared for a gig, how to avoid certain situations that should be avoided (getting too drunk, hitting on the bouncer's girlfriend, etc), and you learn how to learn. Sure I made a few mistakes along the way but if you learn from them you can call it "experience". If you don't learn from them then it's a "habit" or an "addiction".
I went on to play in original bands with guys more my age. We were all late 20s at the time. We practised regularly, hauled our gear all up and down the clubs in Hollywood, and learned how to be broke musicians. Now, in my mid-50s, I'm back in a cover band having a ton of fun and actually making enough money for it to be worth my while.
I would recommend getting out there and paying some dues. Who knows? You just might enjoy it.
Good luck to you. Break a leg.
Thank you for your indulgence,
BassCliff