All of the jokes were taken from comentary in: http://ask.slashdot.org/story/10/08/29/1710203/What-IT-Stuff-Should-We-Teach-Ninth-Graders

The OP asked: “what IT stuff should we teach to 9th graders?”

backups are important.
Yes, the 11th Commandment: “Thou shalt make backups” Unfortunately, it was on the third tablet…
Sorry, that was the OLD Testament. According to the NEW Testament, only Jesus saves.
Not to worry. You can rebuild the third tablet by XORing the odd bits on tablet one and even bits on tablet two.
And thus, there shall be no backup!

Aside from the jokes, the thing that really matter:

Backups are meaningless. Being able to restore is important.