How true, but why?
I can remember yesterday if it was a couple of weeks ago...
But I DO know, from family stories, that my great,great grandmother, at the end of her VERY long life, could remember things from her early childhood, as if they happened yesterday, but had difficulty remembering things that had actually happened yesterday!
Perhaps,that as children our brains are hardwired to learn as much as we can and easily, but by the time we are in our 90s, there's just so much stuff already stored therein, we forget the "new" stuff.
If you have a better explanation, I'd love to hear it.