The first time I ran into a computer which I was expected to use I had to turn to my neighbour in the class and ask 'How do you turn the thing on?'. I did have an excuse, it was a 486 with the on switch on the back panel !
Everybody's experience is different. I started by doing an HNC (sort of a senior technician's qualification) in the gentle art of the maintenance of computer controlled machinery and bought a 2nd hand computer to do my course work on. More flexible than trying to find time on a college computer. Then it needed a bigger hard drive and I installed a whopper of a 105MB hard drive. Picked up the theory mainly in class and the practical by building and upgrading computers for myself and friends, and sorting out problems along the way.
But I would not regard myself as expert, a competent amateur at best, and I have a fairly good idea of my limitations.