I have a theory that I'd like to share with you.  It's my belief that musicians have up to 4 phases to their careers. 

Phase 1:  IDEALISTIC
The first phase in every musician's career when they get into a band for the first time, maybe watch "Bill & Ted's Excellent Adventure" and start to think that, in fact, their music will change the world just like "Wyld Stallyn" did - or at the very least, change the way people listen to music.  This is followed by:

Phase 2:  REALISTIC
Musicians grow up either by age or maturity (usually more the former than the latter) and realize that their music won't change anything, but it might be fun to do and maybe put some beer in your system and money in your pocket.  Around this time, you start dealing with club owners / promoters / agents, who can be an unscrupulous bunch.  This leads to:

Phase 3:  CYNICAL
This is the hardest phase to overcome.  After getting shafted or screwed around one too many times, you start to become embittered by the business and resentful of other musicians for their accomplishments.  One of three things happen at this phase. Number one, they stay in this phase, constantly ask "Why not me?" and hate everyone and everything.  Number two, to put it into a cliche, they 'cut their hair and get real jobs', turning their backs on their talents and the reason they started doing it in the first place. 
Number three is what we should all strive for, which is to move on to the final phase:

Phase 4:  PHILOSOPHICAL
Otherwise known as the "Shit Happens" phase, this is where you realize that it's the music that matters.  Sure, you get screwed around every once in a while but SHIT HAPPENS.  You get passed over for gigs or deals, but SHIT HAPPENS. 
In other words, you get perspective.  You realize that by doing this for a living you stand to get the biggest payout of them all - self-fulfillment.

As for me, I try to hover around phase 4 depending on the day, but I've got a mantra to help me through:
Live to play
Love to play
Play for love. 

Later - T