Sometimes little mess ups happen in life, but sin goes way beyond "that wasn't wise" or "I should have done something differently." Sin is defined by what God isn’t; it is anything out of sync with the character of God. Sin is me going against God; it is when I do something outside the design of God's intended/created purpose. God's desire is that we "come clean" by getting rid of the sin in our hearts and lives. As we “come clean” with God, our relationship with Him will be restored/renewed/refreshed and grow. You may very well find it feels so good to get rid of the crud.