Oh my goodness - I have spices that are several years old and still fragrant. An Indian friend gave me a curry powder 7 years ago and I still use it. (Can you tell how often I eat curry?)
I found a great deal on dillweed online and didn't realize how much a pound of dillweed actually is. I'll be using that until the day I die. (I do use fresh dillweed when making pickles.)