I still have a folder full of notes from several of my university courses, grouped by course. Some of it is source code (either the lecturer's or my own); some is assignment text (in a mixture of plain text, PDF, legacy .doc, etc.). There aren't any repositories because this was many years before Git existed and professors back then apparently didn't think we needed to be taught about the systems that did exist.
But why not keep it? The whole collection is smaller than, say, the OpenBLAS shared library that comes with a NumPy installation. It's maybe 1% of the size of the ISO for a modern desktop Linux distribution.
It's part of a folder with even older stuff - all the way back to toy Turing programs I wrote as a child. There are countless random files that are probably poorly organized internally, that I'll likely never revisit with any good reason. But the whole thing is less data than I'd likely end up downloading if I spent an hour on YouTube or Twitch. The ability to store it permanently costs me literally pennies, amortized over the cost of the drive.
... And yet, the size of modern applications still bothers me. It feels almost disrespectful, somehow. Old habits die hard, I guess.