system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do computer hard drives start at C:\?

Exactly what it says. Why is there no A drive? Or B drive? And what would theoretically happen if I managed to get 25 drives into a system, at which point it would need something beyond "Z" drive. 

EDIT: Rip Inbox, I've never gotten this many replies.
gpt
In the old days, "A" was your first drive, and it was a floppy disk drive.  Then you started getting fancy and having a second floppy drive, which was "B".  Eventually you got rich and bought a 10MB hard drive, which was "C", to go along with your two floppy drives.  Then floppy drives disappeared, but the convention that "C" was your hard drive remained.