Write your own definition of success before someone hands you theirs.

A definition arrives whether or not you write one. School, family, adverts and whoever is loudest supply the default, usually some mixture of money, titles and being visibly ahead, and because it was never stated you end up chasing it without having agreed to it. Writing your own does not make you immune, but it gives you something to compare against. A borrowed definition can be satisfied and still leave you flat.

Write three or four sentences, specific enough to be tested: what your days look like, who is in them, what you would not trade. Keep them private, and read them before any big step.