Lots of us have no idea of what we are doing ... initially. That is why we ask questions and for help.
Whilst I see the irony (and humour?) in the post Woolwell made it may be worth reminding some of the experts on this site that there are others who are desperate to learn about their machines and the problems (some of `their` own making) that require good, competent help in resolving them.
As for `having a useful need` for a computer, well perhaps the modern world is to blame as communication, information and intelligence are all gained (almost invariably) by using electronic means these days. Unless there is a suggestion that we should all return to books, letters and asking questions!!!!
I thank those that provide unstinting and valuable help to me in my hours (plural) of need.