[bstpierre]

In 1993 my freshman CS class was taught in scheme. All of our assignments had to be developed and tested on some shared Digital machine running Ultrix. The scheme interpreter was kind of slow to start, especially when there were 20+ users logged in. Helpfully, our TA taught us how to ctrl-z to suspend the interpreter, then edit our program in vi, and then "fg" to get back into the interpreter.

Unfortunately the fg part of the equation was lost on about 2/3 of our class... after editing they would start another scheme instance! I recall being in the terminal lab the night one of our first assignments was due, and the machine slowed to an absolute crawl. Can't remember exactly how it was resolved but I do recall being taught how to look for classmates running two or more instances of scheme to remind them about fg. (Also not helpful to machine load: "solutions" to the 8 queens problem with infinite recursion. The real lesson here was, in later years, to not be logged in on nights when CS 401 had assignments due.)

[chiph]

I had a classmate who did her assignments in Ada. The compiler & linker would bring the school's Data General MV/8000 to it's knees, as it swapped out other processes to make room for it. Every 30-40 minutes we would have a coffee break forced on us.

[donatj]

When I was first learning Linux around 2006 I somehow got the idea that Ctrl-Z was the way to exit programs. For maybe 3 years, I would just Ctrl-z my way out of programs.

Luckily I worked almost entirely over ssh so I presume the suspended threads died with my ssh session exiting each day.

[gte525u]

I had a similar story with a friend in college in the 2000's. He would always hit Ctrl-z'd to "close" emacs when logged into the server which would've been fine if he wasn't using screen or tmux as well. At some point, he was using a ridiculous amount of RAM on the server and the admins suspended his login to force him to come in.