Technically speaking, no, the water molecules themselves don't expire. They aren't like milk or a banana that will rot into a mess. However, the experience of drinking that water? Yeah, that can definitely go bad.
Think of it this way: you wouldn't want to drink a glass of water that's been sitting out on your nightstand for three weeks, would you? The water is still wet, but something feels off.
What Actually Goes Wrong?
It's not the water that spoils—it's the bottle and the environment. Over time, the plastic bottle can start to leach tiny amounts of chemicals into the water, especially if it gets warm in your car or near a sunny window. This can give the water a weird, "plastic-y" taste.
Then there are the invisible gremlins: bacteria. Every time you put your lips to that bottle, you're introducing microbes from your mouth. Give them a few days in a warm, dark bottle, and they throw a tiny party, multiplying like crazy. The water might still look clear, but it becomes a germ soup. Yikes.
So, the water hasn't "expired" like a carton of eggs, but its quality and safety have taken a nosedive. It's more of a lazy expiration—a gradual slide into "meh" territory.
