I have a long history of keeping leftover material just in case. Timber, screws etc.
The practice comes from my Father who kept everything, a hangover from poorer times.
When I need something and it is just there it can save time and money however it comes at a storage cost evident as the untidy collection of things in my garage.
We all have clutter to some degree be it physical or psychological.
The occasional spring clean can be cathartic and freeing.
What are you holding onto that might be well past its use-buy date?