The problem is that there is too much to learn. This is the fundamental difference between the information age and other times. There is too much to learn in the information age. People pick up most of what they need to know on the street corner, or alone making many, many mistakes. The right information is always somewhere fairly close, perhaps as close as a co-worker.
Computers can do a zillion things.
Everybody needs something different. Read it now, and you would laugh and laugh. Whatever I do know has an extraordinarily short shelf life. The hardware cycle is about every 18 months. Software undergoes major revisions every two years.