I don't keep a lot of "stuff". I have kept a very few things from my childhood that are sentimental to me or that I think my children would enjoy having later on. We are pretty big on genealogy and family history in my family so old letters and pictures and stories are interesting.
But that's also what albums are for. I wouldn't want to just have a box o stuff (or a house full of stuff!) for my kids to have to go through when most of it wouldn't mean squat to them.
My parents kept all the birthday cards that I'd been given as a kid from aunts, uncles, grandparents, etc. If there was a letter enclosed, I kept the letter but honestly I pitched all the cards. Not because I'm not sentimental, but because I didn't have the room for them and NO ONE else but me would care about those cards!! (except for the potential collector value, but that didn't even occur to me at the time).
I go through my house and belongings at least a couple times a year and I'm pretty ruthless in getting rid of stuff. I do have some things that I've kept through the years that have no other value than sentimental, but all the stuff I've kept would fit into two small moving boxes, so I don't think I'm doing too bad :mrgreen: