As a kid I never thought about saving the boxes to my Atari 2600 games. Most of us back then kept our games in plastic holders, or shoe boxes, or drawers. I don’t think most of us had the “collector mentality” back then. A day or two after opening them, the games went in the drawer and the boxes went in the trash.
The manuals, however, were important. Take Space Invaders, for example. Space Invaders has 112 different variations. Along with the “normal version,” there are versions where players one and two alternate turns, versions where they compete at the same time, versions where they complete at the same time and alternate shots, versions where one player moves with and one player moves left, versions where players alternate fire and controls, versions where one version moves and the other player fires, versions with moving shields, versions with zigzagging bombs, versions with fast bombs, and versions with invisible invaders. Without the manual, players would have no idea which version of the game on the cartridge contained which features.
The manuals above are mine. Some of them I got new way back in the late 70s. Some of them I picked up at garage sales from other people who managed to save them. Ironically (or perhaps sacrilegiously…), I store them in a padded Nintendo carrying case. To be honest whenever I need to figure out a game’s settings I typically just visit Atari Age, but I will always enjoy thumbing through those old, glossy pages and looking at the way things used to be.