Yes to answering every email that lands in the inbox.
Yes to everything that someone asks you to do.
Yes to every invite to grab a drink, coffee, or dinner.
Yes to every water filter conversation.
Yes to finishing books you realise you don't like half-way through.
Yes to taking on more responsibilities at work.
Yes to doing more chores at home.
Yes to running longer.
Yes to cycling to work.
Yes to playing football.
Always saying yes is an easy strategy, until it leaves you so overwhelmed that you're only doing what needs to be delivered/completed right the next moment. And when that gets too overwhelming, you stop caring about what needs to be delivered/completed next and only end up doing what's easy.
You've probably experienced it in college. If you haven't paid much attention to your courses all through the semester, you only do the things that will help you scrape through the exam the next day. And if you have exams of three courses instead of one the next day, you just give up and watch a movie instead and decide to wing it, as you don't foresee any rewards for any amount of effort you put may put in at this point.
Always saying yes will lead you precisely to this point. When you decide to take a step back and start over. So go on ahead and say yes. Say yes to avoid the regret of missing out on something that might potentially happen if you say yes, and end up on this path. Richard Branson has said what he has said assuming amazing opportunities don't come your way often. The mere act of recognizing an 'amazing opportunity' is deciding what is worth saying yes to.
Or start paying closer attention to the things you're saying yes to.