Here’s a bit of numerology for you. Today marks 17 years, one month, and 29 days since Mac OS X 10.0 was released on March 24, 2001. That’s a strangely odd number – 6269 days – but it also happens to be the exactly length of time between January 24, 1984 (the launch of the original Macintosh) and March 24, 2001.
In other words, today the Mac’s second operating system era, powered by Mac OS X (now macOS) has been in existence as long as the first era was.
Time is a weird thing, and it truly doesn’t feel like OS X is that old.