The part that matters happens when nobody's looking. It isn't the win you can point to, or the moment somebody finally noticed. It's the morning you got up tired and went anyway. The week you held it together when it would have been easier not to. The day you showed up for your people when nobody was checking.
You don't get credit for any of that. That's the point.
Most people stop somewhere in the middle. Not at the start, when it's still new and you've got something to prove. Later, when nobody's pushing you anymore and nobody would notice if you eased up. That's where most things end.
The ones who keep going aren't tougher than anyone else. They just figured out earlier that nobody was ever going to clap. So they stopped waiting for it.