Driving a 3 ton truck with air brakes when I was aged about 20 and temping. The agency thought it would be a Transit and they sent me along to a company who supply pharmacies and hospitals with all the stuff like cough linctus. The depot driver told me I would crash the truck within a week as he handed me the keys, I didn't crash but had several near-misses and learning the routes while driving the truck and doing the drops was the most exhausting thing I've ever done; I wasn't finishing until eight in the evening for the first week. The truck had an incredibly stiff throttle which made long motorway drives painful but I found a wad of foam rubber behind the seat which, judging from the fold marks, the regular driver had been folding in four and wedging between his knee and the dashboard. I didn't know trucks were limted to 40 mph on the A6 so I used to bomb along at about 55 in the outside lane, foot wedged solidly on the throttle, wondering why all the other trucks were going so slowly. I soon learned that in a truck you NEVER go forwards into an unknown place, they are actually remarkably easy to reverse into small spaces using the mirrors and one one particular day I reversed in to drop some stuff at Stafford General Infirmary but couldn't understand why the truck seemed reluctant to move so I put on the brake, jumped out, did my drop and realised, as I walked back to the truck, that the top of the box had come to rest against some scaffolding, which it had bent round and was in the process of pulling away from the building. I jumped in and drove of as fast as I could. I nearly ran over an old lady on a zebra crossing when my brakes locked solid and I skidded half way across, coming to a stop with her looking right up into my windscreen.
I definitely shouldn't have been doing that job without any training or experience.