Should I say ‘Yes’ to everything?

I always remember people saying to me, "If you are saying yes to that, you're saying no to something else." And I always think about that, because I'm always like, "Okay, I can say yes to this, but I've said no to that. Is that where my priorities should lie?" And having that conversation with myself then enables me to go, "Okay, yeah, that is where my priorities lie. And I've made the right a choice."