I have a tee shirt that says it all:

If you make it idiot proof, they will come up with a better idiot

I write pages of documentation, including screen shots to note each step and I still get calls that start with "Where is the file menu?" I have actually fired a client because they were too stupid and no amount of money they paid me was worth the 5 hours a week I had to spend on basic computer skills. My new client contracts inform clients, that if I have to teach them basic computer skills, I will bill them at $300.00 per hour.