As part of my engineering apprenticeship, I was sent to work on a train depot. One day, a mentor of mine called me over and said "Kid - can you go and see Mr so & so and ask him for a long weight?"

I, without thinking about it - went all the way across the depot found the gent and asked him for a long weight. He looked at me, a little bemused - and asked me if I knew what the weight looked like. I said no. He continued to inquire about this weight - it went on for a few minutes until I realised my stupidity. There is no such thing as a long weight - only a long wait.

Needless to say my mentor had a huge laugh together with his mates at my foolishness.

Sometimes things really are quite simple.