The apprentice system is what developed the drivers. You have to understand that back in the day apprenticeships could last DECADES. I grew up in a tiny village in the UK with a major rail junction and pretty much all the families there had worked in the industry for at least one hundred years. Most of the drivers were 40+ before they became drivers. Most were apprentices for 20 years. The story I was always told is the test they were given is to stop a fully loaded passenger train so the door of the first carriage would stop right in front of the inspector with no inching up. Clean stop from cruising speed, inch-perfect.