I see these words a lot on the groups I'm part of on the internet. On the internet primarily, there is a lot of explaining being done. My in real life groups have a more don't ask, don't tell policy mostly.
The questions I see being asked over and over are:
1) why do you need it?
2) where did it all come from?
3) how do you afford it all?
4) where do you keep it?
5) how do you keep your spouse/other family from getting wise?
6) what is the benefit of it?
I am choosing to start with 2. Where did it all come from? This is a mixed bag of answers personally, in real life groups, and online.
The basic answers are:
3) thrift stores
4) Craigslist and other sites like it
5) auctions, eBay and real life ones
6) "inheritance" from family and friends and others who know you knit or crochet such as church members, who have stopped for one reason or another and want the yarn to go to a good home
7) special trip or vacation purchase
8) impulse purchases
10) winning lotteries of various types
And this just touches the tip of the iceberg of ways your stash can be built.
The questions of incredulity are the ones I see next most frequently. Why and where do you keep it all?
The whys are varied but can be summed up in a few main reasons. I like it. I'm storing away for lean times. I needed a couple yards to finish a project and this whole big skein was left. I saw this new to me yarn and have to try it. I'm going to sell .... and this is inventory for that.
Recently my knitting guild held a topic just about organizing and storing stash. I was one of the presenters. You can organize however it makes sense to you. Anyone who says you in your own home must do it their way either needs to be paying ALL of the bills or butt out. If you share your stash, that is different. Input from all contributors and users should be considered. Ok I'm down off the soap box.
Storing stash.... how much do you really have. This is best done when alone. Gather all the bags, skeins, odd balls tucked away, wips, ufos, hibernating projects and things needing frogged. You can now see how much you have. This can tell you what your oprions are for storage. Will a couple of plastic totes do the job? Do you need a whole room?
If you decide plastic totes are the answer for you, consider all implications. How many will you need? Am I willing to have that many stacked up and then unstack them because I need some from the bottom box? If you have a lot, consider the reclosable bags that air can be removed from. They can save space in the totes. Use smaller bags so you can see what's in each one. These can also protect from insects and flooding. It happens whether we want it or try to prevent it. Can a second hand dresser be better use of space? These can certainly be a nicer to look at option. You can find lots of ways to change them up online.