Having a long history of using computers seems to make it easier to slip up in terms of storage sizes. A reasonable size for a hard drive these days is a terabyte. I find it surprisingly easy to slip up and refer to a gigabyte. That’s a thousand times smaller, but still sounds reasonable to me, because I was around when a 1Gb drive was quite big. Almost unimaginably big, in fact. I was using computers when a 1Mb floppy disc was considered quite high capacity – you’d get pretty much anything you could think of one a single floppy.
My first computer had 48k of RAM, and used cassette tapes for storage. My first PC had a 40Mb HD, which was only bootable when set up as a 30Mb HD. I did that, because 30Mb was plenty big enough. My next PC had a 105Mb drive, which seemed ok for a while, but I then added a second drive, 120Mb, to give me a bit more space.
So 1Gb has sounded like a huge hard drive, and so has 1Tb.
(The photo is the WEEE Man, at Eden Project, a sculpture made from discarded electrical goods, including lots of old computers and components.)