What is the longest validity of a passport?

Okay, so you're wondering about the longest a passport can last, huh? It's actually a bit tricky, not a one-size-fits-all kinda thing. See, it depends on how old you are. Grown-ups, like anyone 16 or older, can snag a passport that's good for either 5 or 10 years. So, boom, 10 years is the max for us old folks. But, for the little ones, the kiddos under 16, their passports only last for 5 years max. Which makes sense, I guess, they change so much in those years! My niece, for example – can you believe how much she grew between, like, 5 and 10?! It's insane. Anyway, yeah, so ten years is the longest you can get, unless you're a kid. Does that make sense? It's a little confusing, I know.