Forgiving...

"It is easier to forgive an enemy than to forgive a friend."
  William Blake

The only thing that I can think of as an explanation is the fact that you can easily forget that enemy, but you will never forget that friend, making it harder to forgive. 

Why is it so hard to let go of ill feelings against someone? I still harbor feelings against a woman who didn't like me twenty five years ago. I doubt that she has thought of me in years!
Me

A Quote About Forgiveness

I can forgive, but I cannot forget is only another way of saying, "I will not forgive". forgiveness ought to be like a canceled note - torn in two and burned up so that it never be shown against one.
Henry Ward Beecher

*I really have to take this quote to heart. I have said that line more often than I care to admit.
Is there one person you really should forgive?

The weak can never forgive. Forgiveness is the attribute of the strong.
Mahatma Gandhi

Always forgive your enemies - nothing annoys them so much!
Oscar Wilde

Forgive and you shall be forgiven.
Luke 6:37

To carry a grudge is like being stung to death by one bee.
William H. Walton

The stupid neither forgive nor forget; the naive forgive and forget; the wise forgive, but do not forget.
Thomas Szasz

To be wronged is nothing unless you continue to remember it.
Confusius