And exactly how do you draw the lines between any of these terms?
A stash seems simple. Having a supply on hand in case you run out. Enough yarn to make a quick gift or pair of socks on a sick day without going on a search for a “good” yarn. A stash is easy to justify and if small enough may not require a justification. I realize it is a current knitting trend to push the limits of what can be considered a stash.
Both hoarding and collecting mean acquiring more than you will likely use. Maybe hoarders imagine they will use what they obtain and collectors actually try not to. In that case, I’m somewhere in the middle.
Maybe hoarders cannot organize their loot and collectors relish the organizing and displaying. In that case, I am the latter. I love arranging my buttons, trims and fabrics almost as much as I do eventually using them.