Having worked in cosmetics and a pharmacy I was aware of shelf life. A lot of people really don't. Back in the late 80's the FDA was trying to get something passed that cosmetics would have to be labeled with an expiration date, but it didn't pass. Maybe because a lot doesn't expires as quickly until you use it, though just browse through a drugstore and you can see foundations and nail polishes separating. Using old lipstick and glosses can give you lip fungus. Eye makeup can give you very nasty infections. Nailpolish or nail cremes can give you nail fungus. And so it goes on and on. Be wise in buying. I love collecting. I love using my stuff. I keep track of when I buy it by taking photos of a haul and keeping them in my Beauty folder. The 2nd week of April is when I change out my mascara. My foundation gets used long before it expires, so no problem there. Same with UD, concealer, powder blushes. I rarely finish a l/s or gloss before it is expired, but I just buck up and toss the stuff and see it as an opportunity to get something new or revamp my collection. I don't use creme shadows and painterly pots only once in a while. I could live without them if necessary. I will never get through all my e/s either, but at least I will have a lot of fun wearing them and trying out different looks and brands for the next year or two before toss time comes! 365 days in a year is a lot of makeup fun!