...it doesn’t mean you have to.
Being able to do something doesn’t automatically make us obliged to do it. This is often the reason people over-commit by agreeing to do too many things, or try to help others who would rather not be helped for example.
It can equally be applied in personal habits. In my case it is book buying (a weakness of mine), as in “Just because I can afford to buy this wonderful book which I never expected to find at this bargain price…, it doesn’t mean I have to.” This has simultaneously reduced my book-buying expenditure, headed off a storage crisis at home and possibly an interpersonal one as well.
On a more serious note, “Just because I can…” (JBIC, shall I register it?), can be used to reduce the risk in some habits that can have have a noxious effect on health: Just because I can have another drink/hamburger/cigarette… it doesn’t mean you have to.
JBIC can even come to the aid of relationships: Just because I can have an argument/say what I think/take this flirtation further…. it doesn’t mean you have to.
JBIC is multi-purpose and almost universal in any situation where free will can be applied.