In my first job after leaving school I worked my way up to a sort of contracts manager for a building company, and I never really knew what I was doing.
One lowlight, when organising the refurbishment of the living accommodation above a pub, I ordered a shower cubicle for the bathroom. I hadn't even considered the thing wouldn't fit up the narrow staircase. The phonecall from the plumber informing me of this, and that they'd left it on the path outside, was an awkward one to field in the middle of the office.
You can imagine the boss' reaction when this cubicle ended up in the office's stores as it was not returnable.
That balls up pretty much wiped out any profit on that job.
I left not long after. I wonder what happened to that shower.