Expiration Dates

I was washing my hands today when I noticed something odd about my hand soap. It has an expiration date. Really. I thought to myself 'I wonder why my soap has an expiration date? Will it no longer function as soap once it reaches that date or even goes past that date?'
I understand about expiration dates for medicine and food. They make sense to me. Medicine can lose or increase in potency once it reaches a certain amount of shelf life. We all know what can happen to food once it's past the expiration date; it can become quite funky and disgusting.
Why the expiration date on soap though? Will it genetically mutate into the blob? Will it no longer clean my hands, but actually, in fact make them dirtier? What evil lurks in having liquid hand soap after the expiration date?
I am very tempted to go buy another bottle of my hand soap and keep it on the shelf until it's past the expiration date. The only reason I don't is that I'm pretty sure that by the time 2010 rolled around, I'd have forgotten exactly why I had this bottle of soap in the back of my bathroom closet or my son would find it and use it before it expired.
I think as a society in general, we have become rather expiration date happy. We are putting them on things that aren't really necessary. Maybe this is why things are getting so expensive. We have to pay for the people whose jobs are putting expiration dates on all our products!
So what items have you found ridiculously marked with expiration dates? I'm glad people don't come with expiration dates because, really, I don't wanna know.