What numbers did you memorize as a kid? How old where you? And why?

For me it my address number at some time in the second grade. I really don't remember exactly the why or even when. Yet I suspect it was the second time I went through the second grade.

As to why I can speculate that it was because that school was so darn far away.

Yet it was most certainly not because of my parents. I doubt mom ever knew our address even decades later. And dad never lived with us for him to memorize it.

So what set of numbers did you memorize? When? And why?