Some stains don't come out on the first pass. Neither does anything worth fixing. I've stood over travertine, marble & terrazzo so far gone I wasn't sure it'd come back. Deep stains, years of neglect, the kind of damage that makes you want to just cover it up instead of doing the real work. Every time, it's the same lesson: you don't win that fight in one pass. You run the process again. And again. You adjust what you're doing if it's not working. You don't quit on it just because it didn't shine after the first try. Whatever you're grinding through right now — a habit, a relationship, getting your footing — same rule applies. One pass isn't the job. The job is not stopping after the first pass. What's something in your life right now that's taking more than one pass to fix?