I used to go into the schools lab when I was a teenager early in the mornings to fire-up msdos 6.x. I would have one computer designated to read to msdos help pages on commands.. And the other pcs around me to test commands on.
Anyway, it took 3 computers of deleting the primary partition on to fully understand what fdisk's purpose was for after making them unbootable. I was convinced that maybe I was using the command improperly.
After, I understood what a partition was :)