If you hustle – all out, fully hustle – and you succeed, then you gain the satisfaction of a job well done. If you hustle and fail, you never have to worry about what might have been if you’d given everything.
If you slack off, you might get lucky and still succeed, but there’s little satisfaction other than the temporary thrill of escaping with your life. If you slack off and fail, you have to live forever with not knowing what you were truly capable of.
Hustling is the best insurance policy against lifelong regret.