A durable nature and a sense of humour and patience are a must in this game! 
Many congrats on passing your class 1.
Piece of advice i would give, would be to count your āsuziesā as you uncouple the trailer, then do final visual check.
I counted them back end of last summer, got to 4, dropped 4th one, picked it up, counted it as number 5. Got in cab pulled away, and bangā¦!!! ABS suzi had snapped frojm trailer and hit the cabā¦!!!
The advice about getting out to look and walking in somewhere first is a life saver/timesaverā¦ I deliver to building sitesā¦some of which are Artic free zonesā¦so they have to tip me outsideā¦!!!
Never assume, always checkā¦!!!
Rgds
Paul