To add to my previous post.
Firstly, I'd like to also state that no matter what you think. You are NOT 'age locked' to your age group. You'll be surprised how much you'll teach people older than you, as much as they may teach you in return from thier experiences. No one person, with the life they are living, will dismiss or discount you because you are younger. Most people in the world are nice and want to help if they can.
Secondly. Do not think because you left school, that your time learning has ceased. Your time learning is only truly begun. Life is as much a teacher, if not more so, compared to teachers in school. So don't discount the experiences you'll definitely have as you find your place in the world. Positive and negative experiences (including mistakes) both hold tools for learning. You just have to be willing to take those lessons to heart.