There was an amazing article in the New York Times awhile back about the students at The Juilliard School who hadn't made it. The premise was, these were all extremely talented, dedicated, hard-working kids who all had an equal chance at "making it". And many of them simply couldn't or didn't.
What were the deciding factors?
At first it looked random and unfair. But as I read the article, it seemed there were indeed sorting factors. And it wasn't necessarily based on who had the most talent or who worked the hardest.
The kids who decided that music was truly what they lived for, eventually found a way to make that work. They didn't all achieve the success they'd originally dreamed of (though some did), and for many it took a lot longer than they thought (though some lucked out and landed in good situations right away). But they all found a way to keep music prominently in their lives and to earn a living with it, and were happy with their decision.
There were others just as talented and driven. But ultimately, they realized they wanted something other than the music and left the industry. Some TOTALLY left the industry.
Many had gone into the field because they were very, very good at music, not because they felt they could not live without it. Some had found the music easy when they weren't faced with such powerful competition. Others just hadn't planned on it taking so long!
There were many who found their hearts really lay somewhere else, and they were ultimately glad they'd left music to find it.
That book I read by Po Bronson WHAT SHOULD I DO WITH MY LIFE? pretty much said the same thing.
It's something I think about when things get hard.