It depends.
Jobs, driving, holidays, exercise, diet, study - all possible to radically overhaul.
Being abusive, manipulative, coercive, violent, long long long term drug abuser/alcoholic with all the manipulation/coercion/abuse inherent in that? Nope.
Being sexually aggressive, with unpleasant or illegal preferences? Never in a million years.
So are you thinking it's too late for you to learn to skydive - or are you being told by a fundamentally horrible person that they've changed/will change if you carry on accepting their wants, needs and temper have to be served and don't divorce them?
If it's the former, go and book it. If it's the latter, no, they can't change, they won't change, they don't want to change, they will never change, so don't waver.