I'm pretty sure there are just as many reasons for stashing behavior as there are types of knitters. For me, I stash because I am frugal. Stashing allows me to knit the things I want to knit out of the yarn I want to knit them in, with less of an impact on my wallet.
When I first started knitting, I was shell-shocked with my first "real" yarn purchase at a LYS. I made the Cape Mod from Stitch 'n Bitch for just about $150. I made it over my Christmas break with my Christmas money. I realized that if that was the average cost of a nice project, I wouldn't be able to make something like that more than once or twice a year. I decided that the rest of the time, I would just have to limit myself to what Michael's had to offer. Fortuntely, a few months later, two things happened simultaneously to make me realize that I wasn't limited afterall.
I made a poncho - a poncho that has never seen the light of day except for the photo I took of it for my FO records. The thing is, the poncho ended up costing me about $60 because of the rate it gobbled up $5 balls of yarn (I had made several trips back to Michael's to get "just one more ball"). Around the same time, I decided that Kyoto would become my next "nice" project. We went to the Grove and I picked out the Cotton Classic for the project, which came to about $50. Wow! I was so excited to realize that the "cheap" yarn wasn't so cheap and the "expensive" wasn't necessarily all that expensive (especially considering it's entertainment value). I also realized that the good stuff went on sale. This let me pick up the nicer yarn that would otherwise be out of my budget at full retail prices.
Since that time, I have added things to my stash as I come across them on sale. I have a pretty good index in my head of the things I want to make, so when I see yarn perfect for it and I have the money for it, I pick it up. It may be several months (or years - my stash is, ehem, healthy) before I know I will knit it, but the yarn is there and accounted for. I would say that 80% of my stash is for designated projects. The rest are things that I pick up if the price is too good to be true and I know I will be inspired by just the right thing some day. And just such a thing happended this weekend.
Knitzalot, Cora and I went on a mini yarn crawl to Encinitas on Saturday with a detour to the Forum shops in Carlsbad/Leucadia (How in the heck I had no idea these shops were here, I have no idea). Anyway, I finally picked up a copy of Rowan 40 from Common Threads. Overall, it is a pretty nice collection of patterns. Sure there are things I would never make, but there are several sure things. The one I became the most excited about was Celtic.
I have been craving a sweater like this - a zip up cardigan that is simultaneously simple and interesting. I think this sweater is so much fun, yet classic. And the best part? I realized I had the yarn IN MY STASH! And since it's been in there awhile, I believe that makes it free. (Just nod. It makes me feel not so crazy.)
So once my holiday knitting is all done, I'm pretty sure this will be my next project. See I made a deal with myself to get the over abundance of WIPs and UFOs in my house done: If I stay focused for the next couple of months, not start anything new and just clear the backlog, I can start something *special* just for me. And I think a pretty Celtic in this yarn, would fit the bill nicely!