Danny Wallace said this quote
“ I mean No is power. No says, I'm in charge. Think about how many times you've said yes in the past year, and how many times you would've liked to have said no instead. Maybe being able to say no is the one thing that keeps us sane. Some people go through their whole lives saying yes over and over again--yes to things they don't want to do but feel obliged to; yes to things that allow other people to take advantage of them, just because that's the way things are, the way things have always been. Some people need to learn how to say no. Because every time they say yes, they say no to themselves. ”