First Class 2 shift (on agency), arrived at client (Bibby), was told, “Just grab the next rigid that comes in”. Never been out on my own, no clue about how curtain-siders worked. Fortunately some kindly driver going off shift saw me looking cluelessly at the truck and gave me a five minute tutorial. Driving that truck out of the depot was one of the most terrifying moments I’d ever had. 
Of course there’s been plenty more terrifying moments since then 