There's nothing wrong with keeping some mementos of your past experiences. It's not like that wooden chest turns you on when you look at it, shells... (hopefully not
). And it's not like that wooden chest drives you to seek after that old flame.
It's just a THING. Sure, it helps trigger memories, but those memories are in your head anyway. If you're going to seek out every item from past relationships and get rid of them, then you might as well get a frontal lobotomy while you're at it, because those memories are still there, with or without the items.
Personally, I've kept things from past relationships. Pictures, cards, little gifts, etc.
And I wouldn't FLAUNT those things in front of a new girlfriend, but I wouldn't get rid of them for her either. I would expect her to understand that my history is my own, and I have memories from before. It's sort of immature to pretend that there's "never been another" or whatever....because we all have histories and memories.
I guess this is all a long-winded way of saying not to worry about it.
So don't.