Emotionally painful dev learning experience: My laptop (and only computer I had in the area) broke at the worst possible time during university and the guy fixing it fucked it up meaning it took even longer. Combine this with:

*Stuck having to learn Android Studio in two weeks to make a whole-ass app with a professor who didn't know how to make a Hello World and gave us no resources. Pair project so I had someone depending on me to do my part, meaning a lot of sharing their computer just to be able to use Android Studio.
*Having to work on another solo project by using various public and awfully specced university computers. Said project involved real-time 3D graphics and was running at about a third of the speed it should on every machine.
*Realizing how much I depended on my laptop for entertainment and that I basically had nothing that could help me de-stress and relax at home.
*Not knowing when the laptop's spare parts would arrive or if the repair man would give me bad news and even more delays.
*A very poorly timed issue in my relationship.

I know university can be stressful even though it never really affected me before or since but man, those couple of weeks broke me.