@tyort1 that's a great way of looking at things.
I'm wondering, do you find you want to keep any old letters or cards?
Let me answer in a bit of a roundabout way, as for me it wasn't an immediate (or obvious answer). But I promise there'll be a payoff :)
I'm recently divorced. When I first got married, my wife and I bought/acquired really nice things. A lot, lot, lot of nice things. To the point that things were fairly cluttered.
At a certain point I became uncomfortable with all the clutter, all the time, in all areas of our lives. So I made efforts to pare down, but these efforts were strenuously resisted by my then-wife.
I didn't understand it at the time but I do now. For me, I only wanted to keep the things that were "the most" beautiful and/or functional. She wanted to keep everything. Because we "might need it again some day", but also there were memories associated with a lot of it. So it wasn't just "we don't need 3 nice knife sets", but rather "oh, remember when we were in Germany with my mom and we got this?"
So after the divorce I still had a fair bit of clutter that I needed to deal with, even though she took like 4/5ths of the furniture and stuff to her new house. So I went through and ruthlessly pared down to only the most essential things and the most beautiful things. I started this during the separation. For example, we had 5 really nice table lamps, but one of them was clearly nicer than the others. So I kept the single lamp that was the nicest.
Here's what happened - the impact of the single awesome lamp was actually increased because it didn't have all the other "sort of nice" lamps taking away from it's awesomeness. It stood out even more BECAUSE it was alone.
So the moral for me - even if you have lots of nice things, the beauty/impact of them is hugely impaired when you have too many of them. Thus, I keep ONLY the very, very, very NICEST things and get rid of all the other stuff that's merely "good".
Now, to bring this back to cards and papers - I take the same approach. I only want to keep the things that have the MOST impact, and bring me the MOST happiness. IME, those things are actually pretty easy for me to identify! So I sort those out of the pile first and put them in the "You won't even get this out of my cold, dead hands" box. Those things are the things I cherish the most and they are sacred.
The other stuff that makes me "sort of" happy, I toss all that. Because I don't want the "pretty good" memories to take up any of my headspace and thus distract me from the "super awesome" stuff that I really cherish.
Sorry for the longwinded answer, but I hope that helps!