I'm a paper pack rat. Keep stuff, especially medical, and bills because I'm never sure if it might be needed. However, with the kids stuff, I keep the stuff that i think they'll want to look through when they're grown, and stack it in a box downstairs. I'll let them have a heave-ho party when they're older. My MIL keeps the stuff the kids give her in a notebook. She's filled one, and is working on the second.