I'm sorry for what you had to go through. I was the abused on in my first marriage. And when I left, everyone left behind thought ill of me - unaware of what had gone on behind the closed doors... A couple had an idea... but most were completely clueless. I would not have left the sinking ship if it weren't for the fact that the other captain was acting thus.
Your young man that you hired reminded me of something else too. I worked for a short time at a hotel as a maid. I very quickly learned my trade to the point that I could teach others.
We had a highschooler "intern" with us (I can't work out how anyone thought this was a good idea, but there you have it.) She quickly gained a bad reputation with the others who trained her who found her lazy.
I had a very different experience. I showed her how to do each part of the room. Then we would split the task, I would do one part while she did the other. I would check her work, then we moved on. I had no problem with her - because I expected her to do what I knew she could do...
Very often, we live up - or down - to people's expectations. When they expect little, we perform little, but when they expect greatness, that is how we perform. (Those who do not perform to the great expectations probably have another underlying issue which must be resolved first.)