Well, I've been struggling with a big pile of nostalgia in my apartment over the past 6 months, and I'm coming to realize that keeping everything just makes you less free in the long run. A big pile of stuff went to used stores and Goodwill this past week and I am already feeling better. Life's adventures stall when you have to catalog crap from all the previous ones.
Also, keep in mind the joy that you just brought to the kid who really wanted that Ernie Ball.