Even though I have rarely taught cooking to my kids , they know how to do it. I remember that my paternal grandfather didn't know how to cook for his whole life while everyone know??? Again, he could never eat anything spicy which I think a kid can eat. Maybe people accomplish something because, curious and unafraid, they just give it a go and, lo and behold, they do it!
Please explain your second sentence. Who knew or didn't know what?