Many people have these - a box that gold assorted things. Things that you might one day need, so they need to be stored somewhere. Just in case. In Finnish that's called miljoonalaatikko (literally a million box), a box of million things. Junk box I think it's called in English.
I might not have a million things in my box(es), but there is a lot of stuff in there. All sorts of pieces that might come handy in right kind of need. Especially as I often find myself tinkering with and hacking things to better suit my need.
Sure, most of those things will never be used for anything. They are just that - junk. But it's hard to know beforehand which of those I will someday need. So better save them all. It also gives a good chance that there is something that wasn't intented for the needed purpose, but can be repurposed for the new need with a little bit of creativity.
Even though those are usually small things it's also ecological when I can reuse something instead of ordering a purpose made part with all the attached manufacturing and transportation costs to the environment (and save a few Euros myself too).