You have the choice to erase one incident from your past, as though it never happened. What would you erase and why?

There are a couple of horrid things that have happened in my life and despite the huge emotional turmoil they put me through, they all contribute to making me, me.  Without them I wouldn’t be so grateful for the things I now have in my life.  Although at least one of them still has the power to bring tears to my eyes, they’ve made me stronger, more patient and forgiving and have strengthened the relationships with the people closest to me.