When someone messes up or wrongs you, do you assume the best or the worst in the offender?
What about when you do the same to others?
You knew the answers to both questions immediately. When others wrong you or mess up, you assume the worst. You assume they have a fundamental character flaw that caused them to do what they did.
But when you mess up?
Just the opposite. It was due to environmental conditions out of your control or to a conscious choice to better mankind with an alternative choice.