Mistakes... Mistakes... Mistakes...!
Knowingly (or) Unknowingly, We all do Sins and repent later. Anyway We can't change our Past, but can mould our Future in bright way leaving behind all dirty things we passed on.
Here is the time to confess yourself whole-heartedly. Confessions are of 2 types in my opinion: A) Open ; B) Secret (You chose what you wanna express).