Was it actually hard to explain? Or was it hard to explain in a way that didn't risk coming across as condescending? I'm "fortunate" in that I never needed to be motivated to study and learn computer programming, so I have about 40 years of computer programming knowledge now. Some of it (cryptography, networking, recursion, pointers) was hard won and took me a long time to grasp. Now I find myself frustrated by the Braeden's of the world who assume that every question has a two-word answer that if I don't know, I'm either incompetent or worse, deliberately hiding something from them.
I can explain memory to anybody, but I have to start from the basics of computation - and if somebody doesn't know what "memory" is, that's where they need to start! But if there's an art form to starting from the beginning without pissing off the person who asked to start from the beginning, I've yet to master it.