People are different, I suppose. Perhaps not in FIRE circles but this is certainly discussed regarding 'normal' retirement, and I don't feel the same way at all. I'm in my twenties, and honestly think I could fill the rest of my life more than once with non-work. Especially if I'm allowed to get paid for doing what I consider to be hobbies rather than work as part of that. At least one of those lifetimes could just be reading!
Do you really find yourself reaching the end of a weekend and thinking Oh thank God I have work tomorrow, I'm so bored?