I think we're talking past each other. I took "expected" to mean "expected by society in general". Teenagers are generally expected to get regular driver's licenses and learn how to drive a car (although many of them don't even do that anymore). It is not common for people to expect a teenager to have a commercial driver's license and know how to operate an 18-wheeler.
Now, is it possible that in the 1970s your dad had an unhinged boss who expected a 16 year old to reliably operate commercial trucks without any training? Is it possible your dad is an exceptional driver who managed to do this? Sure, both of those things are possible. Is it a reasonable thing to expect from any randomly selected teenager? No.
