Saying yes to everything does not imply that you are courageous enough to face it; sometimes you will end up unhappy because of the outcome that you could have avoided in the first place.
I’m not a natural at saying no, but I’m working on it. It is not easy saying it directly as it could be misinterpreted by someone.
Remember when you were already overburdened with tasks and work and your boss asked if you could do more jobs? You said yes, so you ended up stressed out trying to figure out how you could do everything at once. Remember when a relative asked you for money and you said yes even though you were still on a tight budget and ended up falling short? Recall the time when you said yes to a request and what could have happened if you were courageous enough to say no.
Saying no doesn’t mean saying the exact word, it could also mean presenting an alternative answer or solution or maybe being honest enough that you can’t do it at the moment.