A popular phrase says that if it’s worth doing, it’s worth doing well. This is true, but fails to recognize the existence of competing demands for your limited resources. To do something well requires feeding it the resources it requires, which necessitates depriving something else of those resources.
The truth is that if something isn’t worth giving everything for, it’s not worth giving anything for. The only proper place anything worth less than everything has is if it serves as a prerequisite to what is worth everything.
The widespread failure of people to see this truth is not due to it being false, but because they don’t understand the difference between a purpose and a goal or task. A goal or task is never worth giving everything for, but your purpose must be, or you are guaranteed to eventually fail—not just at your purpose, but at life.
Your purpose must be existential. Your life does not have inherent meaning. It has the meaning you assign it through your adopted purpose. If you want your life to be worthwhile, you need to adopt an existential purpose. What isn’t worth dying for isn’t worth living for.