One of the problems with being creative is that you also tend to be discontented, and IMHO discontent is almost essential to significant creation. I'm not sure of this, but I also think depression is endemic among creatives, which exacerbates things.
As you grow older (I'm now officially old) you of course still think you're 35, but you're not. And you want to behave like a 35 year old, including all those things that cost money that you now don't have. But...even though you may now be unhappy with the state of your income, would you really rather have spent those years between 20-60 sitting in a cubicle somewhere processing some paperwork/screenwork shlt you never cared about, so that when you turn 65, you can have a better income? When you start to feel that kind of discontent, lean back in your easy chair and think about all the great blonde tits you got to see, that you never would have seen in a cubicle processing shlt.
I have to accept that this is laced with more than a modicum of truth.
The fact is that of the really, really seriously rich I have known through my life, not one was a happy guy either. (Nor were the wives.) Granted, they did have the toys I could but envy - until I realised those toys were, in fact, liabilities even to them - making me wonder if the truth is that happiness is always but a dream, an illusion that forms part of the force that keeps us truckin' even when little proof exists to make us believe the effort remains worth it.
There may also be a difference betwen male and female ideas of contentment, not that contentment is happiness, exactly, but perhaps a kind of sub-section of it. My own wife seemed to be entirely removed from any visible or otherwise discernable sense of envy at any stage of her life, and I met her when she was fifteen. It would be a delightful conceit to think myself the source of that satisfaction, but reality tells me that it was all part of her state of mind, her spiritual makeup, as it were, one of the very facets of her being that attracted me in the first place. I remember that during the first flushes of some kind of business success I bought her a Rolex; years later, during a trip on a friend's boat down to Gibraltar, we were walking through that dismal port and I bought some Ray-Bans. I saw a Rolex dealership and we went in to compare prices with there and Mallorca, and I asked her if she's like to trade her watch for another, more expensive one. She looked at me in surprise and asked why? The one she had was perfectly good, and meant something to her already. I felt a bit stupid, like I'd somehow missed the point of it all. But she also made me feel very happy that day.
Regarding depression: I gather that some believe it to be a clinical state rather than a passing phase; my own manner of looking at this is a graphic: a straigh line running left to right (or the other way around if nature made you a left-hooker) represents the normal state of being. Points that find you above that line indicate happiness and those below it unhappiness. If life forces you to spend a lot of time below the datum of norm, then you are entitled to feel depressed; if you find yourself living on the datum line, then you are living the normal life of most, and if you find that you spend much of your time above that line, then you are either very fortunate, on something or just deluded.
Whether a mild depression drives creativity, I can't say; but I do know that dissatisfaction with life in Glasgow led me to seek out or, rather, create for myself client assignments that took me travelling abroad. I'd travelled a lot as a kid, so perhaps it didn't seem as unlikely a situation to me as perhaps to others who had always remained where they had been born. Travel, too, becomes a sort of compulsion, and I can remember myself, several times during flat years, gazing up at aircraft and wishing like hell I was airborne too, and off somewhere to work.
And they say there is no God?