What I have done is take a photo of each box, then stash the boxes in the false roof or out of the way and forget about them. Then at least I have a record of what I've got, so if I ever get the urge I can remind myself what I have. It is also good if I get a nostalgia pang every now and then, just by going through my album of game boxes. What is an eye opener however is that even with these big box games bought before Steam sale binges were even a thing, many have never been played, still waiting for when that retro PC I started building 3 years ago gets finished.