My first semester in college I had a six-week Saturday course on how to use UNIX that ran from 9-12. The professor hada habit of going at least an hour over time each week, so by the fourth week we're getting a bit tired of it.

That particular session, right at noon, he decided to teach us how to message other people on the network. Finally, we made our way over to the wall command a half hour later. Bored to tears, I type the following into my console:

wall "Are we done yet?"

Suddenly, the projector updates:

Kaji says:
"Are we done yet?"

Not realizing my name was going to be attached to it, I sank back into my seat a bit. The professor glared at me for about 5 seconds, then promptly wrapped up. Future class sessions ended on time.