My sister kept a pack in her freezer (I guess to keep it fresh) for about a year. She forgot about it until she was cleaning and found it. She was able to throw it away then.
Did you keep anything as a reminder to never go back?
I don't keep anything special around. I use pretty or souvenir ash trays for jewelry and other useful things. But why is it that when I was smoking I could never find a lighter but for several months after I quit they were turning up everywhere? I have a drawer full of the things.