Google reveals various versions and sources of the exchange. Here's mine:
Vonnegut: Can you believe this guy? He makes more money in a single day than we'll make in our entire lives. And you wrote Catch-22!
Heller: Sure, but I have something he'll never have.
Vonnegut: Yeah, Joe? What's that?
"I'm working on my second million!"
(pause for people to act impressed, while secretly loathing you)
"I gave up on my first."
I'm at the spot in my career, where I don't want any advancement or promotions. I'm happy doing what I'm doing. I've got a nice nest egg saved up, so money isn't that big of a motivator.. Really at this point my career is on cruise control, just biding time until I can retire. I'm still learning new technologies, but it is because I want to, not because I have to. Really takes the stress off.
I then take the current value of my savings, plus future planed savings and estimate their future value using several different rates of return. That gives me a savings rate that I need to shoot for, which I generally try to exceed that rate.
Being content and being able to say that you have enough is probably one of the best thing you can do for your mental health. And happiness.