Yarn gluttony, or the treachery of the trunk purchase...

For those of you wondering what the devil a 'trunk purchase' is, it's basically a situation where when bringing a newly purchased item into the house would cause your spouse so much tsorris (if he's Jewish) or agita (if he's Italian-American) that the best thing to do is to leave it in the trunk of your car until the coast is clear and you can sneak it into the house without causing him pain. How thoughtful of you!
When does stash enrichment become gluttony? When is too much of a good thing not a good thing? In continually acquiring yarn because a. it's on sale b. so perfect for some imagined future project c. terribly fabulous/soft/unusual/hard-to-find or d. you see some other intrepid knitter who must know something you don't buying it and suddenly have to have it, are we setting ourselves up for a lifetime of excess, awash in projects that will never become realized?
I am a yarn glutton and am on the verge of experiencing yarn gout.
The yarn you see pictured above is one hell of a trunk purchase, all gleaned from my playground pusher errr LYS which was having a mega-sale this week. Note it's location: the trunk of my car! Most of it is Swiss Chalet (discontinued!), Landlord (also discontinued!) and Two-Two (discontinued as well!) and unless I plan on spending the summer in Australia where the temperature would necessitate heavy woolens, these projects are all going to be for next year...