For me was not grand parents but my dad was referring me ALL the time to other people that went to his workshop that I "know about computers" (almost is some sort of arcane knowledge). I remember once somebody approached me with the typical question:

• Are you the one that "knows about computers"?
• (cringing inside already) yes that's me
• You know, I have this fridge that won't cool....

I just left even before he finished the sentence. My dad later that day asked me why I was rude to someone (I know it was this guy). I just told him "imagine you know about cars and somebody asks you fix their fridge". Didn't even need to say more.

So for some people in my place, " knowing about computers " means arcane knowledge with nearly everything with a digital screen on it.