This quote comes from Janis Joplin, who argued you shouldn’t settle for anything less than what makes you happy. If you do, that’s what you become.
Everyone has to settle for something at some point. You can’t have everything and you can’t go on without compromising for your entire life. Nevertheless, you shouldn’t just settle for less than what makes you happy. Instead of choosing what you think is best, you know you’ve got what you need when happiness will follow.