Can someone explain this to me?

Ever since I came to this sub, I stumbled upon a few people who decided one day to quit their jobs to make a game or multiple games. I never understood what kind of person you had to be to willingly drop your biggest/only source of income to go make a game (from my pov).

Can someone put this into perspective for me? I’d like to make a game one day as well but I cannot just quit my job like others can.