Hitting milestones. Reaching new levels. In whatever you do, theres always another level to reach.
This may mean a new level of intensity, a new level of confidence, a new level of mental toughness, discipline, strength, etc.
You may not even realize at the time what that next level looks like for you. It may take some time just to identify it before you even set out to achieve it.
But once you do reach a new level, understand that yet another level exists beyond that. And once again you are faced with the choice of seeking it out or settling for complacency.
There are people who spend their entire lives content with complacency. Don't be a statistic.