...in a former life I was a truck driver and I drove the yeast tankers in and out of Burton-on-Trent.
First day on the job I got given the keys and sent of on a trip to various breweries with no training, just the advice that the brewery staff would know what to do.
First pickup in York and I am met by a brewery guy who has only a rough idea of what to do as well and we unship the pipes, connect up to a vat of foul smelling waste yeast and switch the pump on.
After a few seconds the pipe is bucking like crazy and the pump is making the sort of noises I only ever heard before when my parents thought I was asleep and me Dad had drunk enough to be able to come within 10' of Mum without being physically sick.
I worked out what was wrong; I hadn't opened the inlet valve on the truck. I leap for the valve and try to open it.... just as the pressure builds up enough to blow the pipe out of the ring mounting, spraying everything in the immediate vicinity with the foul gloop.
I was covered from head to foot (quite literally; I looked like a melted mars bar) and had to be hosed down by the giggling brewery staff. What's more I stank of marmite for about a week afterwards... although the missus didn't seem to mind over much.
Haven't been able to go near the stuff ever since for some odd reason.