Saying no

I'm one of those people who wants everyone to be content, so saying no isn't easy for me.  I'm not referring to my kids, I can say no to them.  I'm talking about the times your asked to bake for something, babysit,  volunteer at school, drive somewhere you didn't plan to go to...you know those things when you say yes while thinking I really don't want to do this.   So today I finally said NO to something.  I was excited about an opportunity that came my way, however the final directions had changed and I was asked to cover something different.  At first I was like, well OK, but finally something in me woke up.  I was like hello... it's really not what I want to do, so NO.  I wonder if this means I've finally become my mother???