Them why is t my hard drive four million kilobytes? We already crossed this bridge with gigabytes, and the course was laid in with terabytes, which I first heard in a business setting over 20 years ago, when that was still a rack of hard disks. Cloud providers and the LHC brought us petabytes, and that was over ten years ago. The “oh by the way the next unit is ‘exabyte’” conversations started around the same time.