All IT professionals overestimate how well users are familiar with computers and how well they can be trained.
In many healthcare settings I've seen nurses have notebooks full of:
"To do X,
Click lowermost left, click second up third to right",
going on in for however many steps the custom software needs to perform things. I've wondered why it doesn't have buttons that does the X, Y and Z that the nurses have made their own 27-step lists on how to do through the convoluted interfaces...
That is the level of user sophistication we need to design for, ladies and gentlemen.