It is easier to try to be a decent person once you accept the fact and admit to yourself that you are a bad man. It allows you to answer a lot of difficult questions with honesty and without shame. It grants a peace, even though that peace is not always the what one might ideally consider as such.
You are who you were.
You are who you are.
You are who you will be.
There is little benefit in crying over spilled milk, beer, or blood.