Hey Jamie, I can definitely relate to being surrounded by kids who are better. Let's put it this way: I began learning piano at 19. That should about sum it up

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Here's where I see a problem in your perception:
he must be very talented and "ahead of his time" if you will.
It's not usually the case that a kid is ahead of his time, but more that he's put in more time. The clock moves the same for all of us, and some simply started earlier or put in more effort each day, maybe they have less of a social life or don't get to play much sports because of it, but you can be sure that they all had put in the necessary work to get where they are. As another pianist, you should know what kind of work it takes to learn music. No need for envy, just understand. Go talk music to one of these kids someday, find out where they're coming from, it can be very enlightening.
Just last Fri I was at a little competition, I was the only adult participant, everyone else was varying degrees of 'younger'

(BTW, I'm now absolutely convinced that the myth of children being less emotional in their playing is pure BS)... Whenever someone does a great job, better than I could do, first I'm kind of pround of them, thinkinging "wow, she really did a great job, it must have taken a lot of effort and determination to reach that level!". Then in relation to myself, I just think "if I keep at it, and put in enough work, one day in the future I can have that myself". It's inspiring to think of it as your own future destination, the price is persistance.
The difference in your situation Jamie is that you were the proverbial 'big fish in a small pond'. So you probably grew up with praise, being the greatest thing around. Not underservingly either, I'm sure you are very good. But it must have inflated your ego, which is now being popped as you leave your small pond and enter the ocean where there are many big fish. So what you must learn is humility, in order to grow you have to recognize where you currently are and work from there.
There's a term called being 'outcome dependant', which is misleading. In fitness they say that the only road to success is when you replace forced will with enjoyment... If you become less concerned with the outcome of winning or being the best, and focus your energies on enjoying the process while you learn, you will paradoxically get there much faster. It's a zen sort of thing. Detach your ego and rediscover the love of music, that is a much better source of inspiration than pride.
I hope this helps and makes some sense for you.