Never ever open a computer while breathing...
I got a ticket to fix a computer from the production line that was turning itself off...
When I opened it, a dark dust from hell came right into my lungs... There were more dust in there than I've ever seen in my entire life... Combined...

I'm still sneezing 3 hours later, and a few black spots keep coming out with everything else...

Cleaning the white board after a problem is solved is still the 2nd most satisfying thing. Closing chrome tabs is still 1st

Had to do something with Xcode for a while now. After 2 hours my tolerance for strange errors, which are solved with cleaning build folder or closing/re-opening the IDE, is used up for the next 10 years...