They aren't saying every person of those generations is the same. Your family is very techy and it makes sense that they'd be knowledgeable, but the point of the meme is that there was a generation that grew up with tech that kinda worked most of the time, forcing them to learn how to use it to be effective, leading to a higher proportion of people knowing how computers work. Nowadays, except if your job is fixing computers, the chance you know them in-depth and how to tinker with them is much lower, because there is no need, they just work most of the time.