I am a little teapot
This is geared toward the prepper newbies, among which I count myself. We have started writing the date we purchase and/or start to use items to see how long they last, especially items which last a while, like laundry soap, toothpaste, etc. We do this to establish baselines to see how much of a given product we need to last a month, year, etc. That way our limited money can go to needed items. Instead of 3 years' worth of mouthwash and a month of 2 cycle oil, we can judge when to buy what, and how much. You old timers no doubt figured this out years ago, but like I said, I just wanted to throw it out there for the newbies.