What does it mean to "Hold oneself accountable"?

What does it mean to "Hold oneself accountable"? I've always thought this meant taking responsibility, for our actions and how we treat others. I have always considered myself responsible, thoughtful and I show respect. I admit my mistakes and TRY to correct them. I am emotional and take things seriously. Apparently I come up short somehow... a friend has pointed this out. I would appreciate the views of others, and maybe I can find what I am missing. After all it is not what we think... it is how others perceive us.