No no no no no no no no no no no no no no no no. This is the word that every toddler masters yet as adults it can be so difficult to say.
If you don't particularly feel like doing something, don't do it!!! Don't do anything out of obligation. This is not selfishness, this is self-care.
"Drop the word obligation from your vocabulary and you will be free of resentment." (unknown)
Often it is not the feeling of doing whatever it is you have said yes to, but the negative feelings you carry that feel off; often feeling as though you have sold yourself out by not listening to what YOU really want. Saying yes through obligation is placing your needs below those of someone or something else. There is a very big difference between saying yes to something because you truly want to and saying yes because you "feel it best you should."
We can still be "nice people" if we say no! This can be programmed into us as a child to be nice people and this can often mean finding ourselves saying yes to everything and doing things we don't want.
We can give MORE to others in an authentic way when we look after ourselves and learn to develop self care. This is where true compassion and caring for others begins.
To use the analogy of a cup, we must have a full cup before we can start sharing. We can't give from an empty cup. .