Lesson #3: Nobody has as much money as you think they do.
The biggest joke to date in the music industry is about the level of wealth the big league guys are supposed to have. I've met a bunch of musicians and a bunch of millionaires. They are usually not the same people.
On the lower end, the guys on their way up are still spending like there is no tomorrow, but most of them aren't getting that island oasis. Most of them are thinking of getting a nice house in Jersey or maybe having a car that's not going to have a hundred thousand miles on it by the end of the year. They're mostly buying better gear and trying to hire people who will keep other people from screwing them in the shower.
On the higher end, the guys on their way out or down, they're just trying to hold on to a reasonable level of income to keep whatever middle class lifestyle they've adopted. Few of these people live with a horde of security people and hangers on. It just costs too much money and uses up what you have too soon. If they're still performing, they still have to come up with equipment, hire staff (managers, roadies, other musicians), pay all the usual travel bills and possibly manage a household.
In the center are the people who've made it, but who are at a career plateau of one sort or another. The smart ones are storing up for the long winter ahead, which comes to almost everyone. The dumb ones will end up playing Tuesday nights at a bar in New York, be glad to get it and reunite with guys they hated back when they had some money to play rural clubs within driving distance.
I've talked to people with Grammy nominations and solid selling albums who bragged about paying off their student loans, not early but just on time. I met a blues legend dying of cancer who couldn't quit working. I've hung out with performers who got upset when they misplaced minor articles of clothing, like socks and underwear, because they were going to have to buy them again. I've been around when the checks have been handed out for a show and watched how relieved some of these people look.
Not all of the stories about musicians getting screwed on their pay are true. Just most of them.