Can you go into detail about the mental exhaustion? So 90% of trucks are semi's on road. Do you think those guys enjoy their job or is it too exhausting compared to a sprinter?
Mental exhaustion is a factor because there's just so much more to keep in mind: logs, permits, lights/tires/brakes/reflectors [got dinged on an inspection when one was missing], all safety equipment, etc that might be inspected at any given moment, whether at a scale, a random, or post accident.
Add to that the numerous truck restrictions on height, weight, axles, width, lanes, even time of day [love the street in FtWayne that doesn't allow trucks from 6PM to 7AM!], and finally, throw in the difficulty of finding a name that doesn't exist [because the consignee was bought out years ago] and a street address that isn't posted, and the stress climbs pretty high - exploring is risky business in a truck. Miss a turn or sign [amazing how many 'truck entry' signs face only one direction] and find yourself in a residential area not meant for trucks....
Do it in the predawn darkness, surrounded by 4 wheelers in a hurry, and you can find yourself chanting "I love my job" over and over to stay calm, lol.
I do love my job!