I'm a roofing contractor, not a pillow expert--but I spend a lot of time helping homeowners understand when something that protects them needs replacing, and the logic is surprisingly similar. Most pillows should be replaced every 1-2 years, though higher-quality materials like latex or memory foam can last 3-4 years if cared for properly. Down and feather pillows might stretch to 2-3 years with regular fluffing, but polyester fill breaks down fast--usually under a year. The biggest sign you need a new one is waking up with neck pain or noticing the pillow won't hold its shape when you fold it in half. To make them last longer, use pillow protectors under your pillowcase and wash them every few months according to the care label. Just like how we tell homeowners that small maintenance prevents big problems, a little care goes a long way. Replacing your pillow matters because you're spending a third of your life on it--poor support affects your sleep quality, which affects everything else. I learned this the hard way juggling early mornings on job sites, kids, and homesteading--you can't function well without decent rest, and your pillow plays a bigger role in that than most people realize.