If you're a dog owner, then you probably think you know everything there is to know about your four-legged best friend. Her preferred kind of human food. When he actually needs to pee and when he's faking it just to go outside. The fact that for reasons you will never know, she growls at tall men in hats. But this revelation about dog years will probably upend something you though you knew for sure about your pup: their age. Business Insider partnered with data company Priceonomics to show us how this whole mysterious human years vs. dog years thing works. Apparently, the idea that one human year is equal to seven dog years is a total misconception. Lies! As the video explains, that would mean that humans would be able to procreate starting at age 7 and live to be 150. Which, as we know, is not a thing. So what's the real deal? Well, dogs just age differently than humans in ways we didn't realize. They age much more rapidly in their first year of life than we do, reaching sexual maturity around age one. And how old they are in human years totally depends on the size and breed of your dog. Basically, the smaller the dog the more slowly it ages, and vice-versa. According to BI, a tiny 9-year-old dog is 52 in human years, while a giant 9-year-old dog is 71. Crazy stuff, right? Now, go give a dog a hug and tell them they're perfect just the way they are, at any age.