First step is to realize what counts as success for you (your answer will be a different than mine than your best friend's), and then judge how much effort is needed and if / to what extent it's worth it.

I am in a position at work that I refuse any further promotion by now - I found that sweet spot that makes me enjoy my day-to-day work, and at the same time I get paid good enough that I don't have serious worries about money. I'm not filthy rich, but I earn more than I spend regularly. Any further promotion would tip the balance adding money that I don't really need but stopping to enjoy my work. I count it as success to be in my place, and that I stopped to try reaching for the stars in time.