Responsibility is all about owning whatever decisions you have made.  When you are a fully functioning grown-up, you take responsibility for your behavior, your actions, your decisions and your initiatives.  So, responsibility really is learning to be a fully functioning adult.  If you say you are going to do something, do it!  If you say you are going to follow through, follow through!  If something is broken on your watch, take ownership for it!  Follow through, show commitment, and avoid the blaming, the whining, and that somehow thinking that making excuses is going to get you results.  Take more responsibility and others will as well.