Better to have not lost, but loved

I was remembering an old friend and teacher today.  I let him and his family slip away, as I have done with so many friends over the years.  Rather than discuss a situation with someone I have disagreed with or whom I have let down, I just disappear.  I do not know why I do this.  It is more than simply losing touch over the years.  I have done this also, but I am talking real avoidance here.  I used to think that all my friends left me.  This had been true in one or two situations.  I took those situations and applied them to all the friends I had let loose.  Now that I am allowing the thoughts of these people I have loved and lost, I feel very angry and upset with myself. 
When I look inside very clearly and consciously I find I am very judgmental.  I judge myself to a very high standard and apply the same judgments to others.  When I talk about the high standard I do not mean this proudly, as if my standards are better than those of others.  What I mean by this is that I am unforgiving and uncompromising in my own head.  If you do not feel or think what I feel or think, then you simply must be wrong or evil.  Rather than calmly discussing the differences, I avoid the discussion all together and flee, either mentally or physically, so I do not have to deal with a reality other than mine. The saying goes " some people are absent even while present" applies to me when there is disagreement in the room.
This happened recently to me with a person who was very old.  I could not throttle her, or beat her up, nor could I calmly change her mind.  When I found out from whom she was receiving her opinions( relatives and up to 30 pieces of mail a day), I was blown away.  I could not even begin to challenge her facts, as she was so sure they were true.  It would have been useless anyway as it was so ingrained.
Tell me, who fights with a 91 year old woman?  It would be insanity.  The real tragedy was that I was so angry.  I never wanted to see this person again.  This is what happens to me, and if I am not in a situation where I regularly see the person, I let the disagreement take over, and forget all the really good parts of the relationship.  The truth is there are really, really good things about each of the relationships I have run from or just let die of neglect. 
I must learn from my mistakes and introspection and find a way to be reasonable in the face of difference.  People have so many wonderful qualities and I must learn to hold these above any mistakes or differences in our relationships.  Relationships are ruined because people cannot find common ground to work from and through their problems. 
I am really glad I am old because there was so much I did not see when I was younger.  I was too busy and always moving forward to take much time for hard introspection.  I thought I was so intelligent and wise then but OH! HEAVENS! What I missed or ignored and now find it so difficult to get back.  I cannot even locate some of my old friends to make amends.  I can however become even more self aware and try not to hurt as many people in the future.