Hay, don't insult Grandma. Why do you assume that because someone is old/older that she doesn't know her way around an OS. This is not an age or gender related matter but a technical know-how matter as noted by several on this thread.
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Yes, that's true. But, isn't it an individual's responsibility to learn at lest the basics of whatever technology s(he) uses?
Yes!
I wish more people would take advantage of Apple's "One to One" when they get a Mac. It's designed for newbees with little or no technical skill. And, for those that can't afford it, there are the free group classes in the store.
However, this does not help the individual who does not live anywhere near an Apple Store or whose health does not let them get out to take advantage of such programs. In that case, there are simple books that beginners can use. Also, many junior colleges (now self-classified as colleges or universities) and even some colleges and universities do give extension courses; however, I suspect these are mainly but not totally for IBM clones rather than Mac.
For those that do nothing to learn, I have little sympathy. But, don't classify them by age or gender, just by ignorance, arrogance, or worse.