We all mess up sometimes. So why is learning to forgive yourself a lot harder than forgiving others?

Today is Global Forgiveness Day. I personally struggle with forgiving others and I am especially hard on myself. But let me tell you it does not benefit my life in any way and I know I've still got a long way to go with forgiveness. So here's a snippet of an article on learning to forgive yourself:

So effective is forgiveness - if we could find a way to learn and teach it - that Stanford University is undertaking a project to learn how forgiveness can enhance health and relationships and even prevent disease.