Take manifest destiny
, and apply it to filling up a hard drive, so that you get something like "downloading stuff (such as movies) because you have the space and/or you were meant to.
"My mom looked at me inquisitively and asked, 'Why do you need a new hard drive?' I replied, 'Hard drive manifest destiny.'"
"Billy just bought his fourth hard drive yesterday; he should see a shrink about his hard drive manifest destiny."