I used to be terrible about saying "no". Maybe it's partly because I'm an oldest and can be a bit of a pleaser or maybe it's because I worked so long prior to becoming a stay at home mom that I felt I should be doing more.
I discovered after awhile though that I was incredibly busy doing a lot of things that didn't particularly feed me. That's not to say that some of the stuff I got involved in wasn't fulfilling. Some of it was. But a lot of it was a slog, not things I wanted to do because they mattered to me but things I felt I should do or just couldn't say no to. So I decided when I turned 50 I would extricate myself from all of this stuff and reassess. Then I got amylodoisis. Thankfully I had already started the extrication process but the part about reassessing and finding out what I was really interested in, what would feed my soul had to be put on hold.
Ironically now I have to say "no" and a lot of the time it's to stuff I want to say yes to. I'd like to be out on the boat with the boys more but I have to be careful about the sun because of the amount of prophylactic antibiotics I take. I have to say no now to many things because I just don't have the energy for them. What a lot of time I wasted saying yes and doing things I didn't really need to do or want to do. Why do some of us need to have something dramatic happen before they realize this? Your time is your currency, spend it wisely.