I'm an engineer for a manufacturing company. We are an importer and nationwide distributor of some very specific types of highly-complex machine tools ("Swiss" machines, for those of you scoring at home.) Part of what we offer is a 'turn-key' package. For that, I will take a part from cradle to grave, so to speak. Spec out tools, purchase and install them, program the machine to make whatever part the customer wants, perform a 100% complete quality statistical analysis of a sample run, and repeat all of this on the customer floor once the machine is installed. And lastly, I train the customer how to use their new machine, even if they did not purchase a turnkey. We also offer week-long bimonthly training courses at our showroom. I say all of that, because after 30+ years in manufacturing, I am in a position to take what I have learned in a variety of disciplines - machining, metallurgy, metrology, statistics, trig, programming - and distill it down to a week of discussion with a group of people with skill levels that may range from: An unskilled button pusher who has a union ensuring he has no need or desire to learn anything at all (because only qc can measure a part, and only an engineer can adjust a tool) all the way to: The guy who speaks in binary, has a tool rep on speed dial, already has the machine running at full production, and only came to training for the free lunches and to find out how to write a custom routine that will text him on his boat when the machine has an alarm. I have to figure out how to keep them all engaged, while also speaking to someone who may have zero competency but actually wants to learn something and really needs to hear it from the very beginning, in small words. I will always start out with "I don't know what you know, so I'm going to start with the very basics, just to make sure I don't leave anything out." Most of the time, someone in the room will say "thank you."