You make things. Hollywood shows interest in these things. Announcements happen. Things fall apart. More announcements. Every now and then some actual money shows up.
When the "big check" does come, you find that, if you add it to everything else you've made in the previous several years, you may just be living above the poverty line.
None of this is meant as complaining, of course. Last I checked, I still get to write stories for a living, as meager as said living may be. I get to work and occasionally hang out with some really cool people. And, every now and then, I get to sit at Chateau Marmont and look at Charlize Theron. Hollywood!