I am now twice as old as you are, and feel damn lucky that I’m still here.
This is what happened since you became me.
You stopped being delusional about being a hero and decided that you’re happier simply being a genuine shmuck.
You believe in God more, not because you are desperate or needed a crutch, but because you did a bunch of research and have absolutely no explanation for a great many more things that you’ve seen since then and now. But God is different, more universal, as is your understanding. Also, God is probably female, but maybe not. You’ll start to have fun not knowing everything.
Those foreign and classic films that you’ve watched, you’ll appreciate them more as you get older. You’ll have less time to watch movies like those, so it’s good you got them out of the way.
The Natural will not be your favorite movie anymore, and Roy Hobbs was an idiot who should have made the right choice earlier in the movie. You won’t have a favorite movie. You won’t need a favorite movie. You won’t project your own personal shortcomings to the protagonists in movies anymore, because they aren’t you, and they were never real.
Speaking of which, you won’t care too much about The Phantom of the Opera musical as much, because, well, see above. You will appreciate Les Miserables, The Lion King, and even Cats more than Phantom. I’m thinking of selling those collectible Phantom of the Opera crap you bought to impress girls. They didn’t work.
You will stop using James Bond ringtones, and you will realize that it’s okay to fight windmills as long as you’re not in denial about it. Fighting windmills is a good fight, whether or not Dulcineas exist.
You will have no problem admitting that many of the things you do, many of the things that you create or design, can be utter garbage sometimes, because you will have created enough to still have a lot of good stuff left after you’ve filed away the garbage.
You will know what old feels like.
You will be glad that you decided against doing a lot of stupid things that you would have regretted, that you’d still be paying for at my age.
You’ll be fatter and uglier and slower, and you’ll have no choice but to accept that.
You’ll be funnier and wiser and overall more talented, and that will be that.
Somebody will invent the idea of humblebrag. Don’t use it. Just brag if you feel like it, and let others judge you however they want to. You’re not going to stop them from doing so anyway.
Since you will constantly have everything to lose, you will be passionate as if you have nothing to lose.
You will have a better understanding of silence.
You will get tired more easily, so when you do have energy you will waste less time on things of compromised quality.
You will NOT automatically become a better person as you get older. If anyone tells you otherwise, disagree with them because thinking like that will make you lazy.
Nothing is guaranteed.