Rolled out a new application I built almost entirely by myself 2 days ago... But my dev group is understaffed and has a project manager who is literally the most clueless person I have ever met, so as a result, we don't have a functional/useful dev/test/prod framework and no standards for how to deploy apps. So my past 2 days were comprised of fixing bugs in the live system that could probably have been caught if I had the time and resources to get everything thoroughly tested. It's stable now, but damn our management for being generally idiots. Our motto appears to be "Fuck it, we'll do it live"

Final project senior year...
Mistake 1: Chose a project suggested by the prof, who did not initially make it obvious that the project beneficiary would be a personal friend of his.
Mistake 2: Nine of us thought this project looked cool and all signed up for it.
Mistake 3: Looked at the code-behind provided for us and discovered that the web-app we were building was... programmed in Java, using StringBuilder to append HTML, CSS, and JavaScript and create its webpages. Which was then decoded and built into a webpage using some obtusely designed compiler.
Mistake 4: Decided to question the reasonability of said project to the prof.
Mistake 5: Did not quit the project as a group and do something else

We all graduated, I think, but a lot of C-'s were had. Fuck that class.

Had an intern go configure a bunch of workstations for our employees over the summer - we gave him a checklist and let him loose.
Several months later... Try to support a user with their workstation and find out that $software isn't installed on said workstation. Check other workstations. No $software on any of them.
Ask intern "did you follow the checklist we gave you??!"
Intern: "Yeah, I followed it."
Ask intern: "So why is $software not installed on the workstations?"
Intern: "Oh I didn't have a copy of $software so I skipped that step."
What.
So he's probably getting shitcanned soon...