No my grandmother is exactly like the OP. She is incredibly intelligent, witty, excellent problem solver, etc. But for some reason when it comes to tech her brain just turns off. She just doesn't want to be bothered. Even though she has used a computer pretty much daily for the past 20 years (she is an editor) even simple tasks like trying to figure out where she saved a document, how to add an attachment to email, or even how to turn on a computer, is difficult.
I think she just thinks it is too difficult to understand so she just doesn't even want to attempt to try to learn it. Give her some tools and she will have a non functional lawn mower motor working in no time. Give her some verbal math problem and she will figure it out faster in her head than you using a calculator. But hook up a cable receiver to a TV that has only 3 cables (one of them being the power cable)? Call the grandson!