There's also addiction to success. If you don't keep getting the success in magnitudes you did before, you will get bored and depressed, so you have to keep going and get it since your brain is wired to seek for that. Your brain and emotions are calibrated to what you got before, it's kind of like drugs.
If you don't have the 10M you won't understand, you would think that "oh my if only I had the 10M I would just chill", but it never works like that. Human appetite is infinite.
The more highs you get from success, the more you expect from the future achievements to get that same feeling, and if you don't get any you will feel terrible. That's it.
Speaking for myself, I'd keep working even if I had 100M. As long as I am healthy, I plan to continue on being productive towards something I find interesting.
What would you be working on though? I agree that I’d keep working if only since I like my work and not having that structure can make your life worse, not better; but if it’s “how I get to 1B” then that’s the kind of challenge that turns me off. I’m all for continually challenging yourself but I don’t want that kind of stress in my life, I’d rather find my challenges elsewhere.
If you don't have the 10M you won't understand, you would think that "oh my if only I had the 10M I would just chill", but it never works like that. Human appetite is infinite.
The more highs you get from success, the more you expect from the future achievements to get that same feeling, and if you don't get any you will feel terrible. That's it.