getting older can be so amazing? you get more familiar with yourself. learn tips & tricks for troubleshooting your own brain. trial & error helps you build routines that minimize discomfort, maximize reward. your preferences/interests don't get set in stone, but you do find out which ones are going to stay with you in the long-term, and which ones are fun but transient joys to appreciate in the moment.
you learn that the world is so much more complex than you were taught, and that that's okay, and that there's an endless supply of things you can learn or watch or experience or think about if you want to. if you're lucky, you loosen up, stop putting so much pressure on yourself. if you're lucky, you learn to recognize that negative inner voice, and whack it with a baseball bat until it hushes up. if you're lucky, you learn to treat yourself gently, not because you are fragile but because you are worthy of gentleness. (i hope you are lucky.)
and some things will change. some things will get better. some things will get good. and maybe you start to recover from the dehumanizing stress of childhood/education. maybe you learn the power of your own autonomy. maybe you learn how to walk away from bad situations (which is a superpower even if you don't realize it yet). and you get to choose your own clothes. and your own food. and which relationships to pursue! and what you do with your free time. and with your life (but don't worry you get to choose that gradually). and that's crazy! and sometimes scary. and extraordinarily, indescribably precious.