I have quite a story to tell in this regard. I started drugs when i was very young and i was heavily addicted more than 10 years. It took me another 3 years to fight against my heroin addiction but i made it.
I am clean now since 3.5 years after a long therapy.
I have work, house and girlfriend and couldnt be more happy. 
I have got to a point in my live where i can accept my past and i dotnt want to miss one thing of it because i dont want my present to be changed…
cheers