I remember when I first retired, I received a flood of proposals to serve on a variety of boards. The pitch was, Since you re retired, you have more time. I smiled politely but firmly stated, No, thank you. After all, I retired to have more free time to explore new things. I d had my fill of board and committee work.
Folks are always kind of shocked to hear one decline the opportunity to serve without an apology.
But I have found that an apology really invites the other person to evaluate whether my reasons for not serving are good enough. Instead I have been consistent with my noes, and it still feels good. Now my public service is as a volunteer consultant. The truth is that because you are so agreeable all the time, your friends might perceive you as weak, an easy mark. Learn to say no.