Honestly, I think the only "opening line" that I have memorized is from a children's book that I loved when I was a wee thing, and still have a copy (not my original one) on the bookshelf, and every now and then I re-read it just because it still amuses me. The book is called "A Little Ballerina" and (if memory still serves) it starts out thus:

Carol and her dog Cindy watched the children playing outside. Carol wanted to play with them but she could not, because her legs were weak. It made her tired to run and jump like the other boys and girls.

Of course, that's why her parents signed her up for ballet lessons, to help strengthen her legs. I could really relate to the story since I had leg braces when I was a youngling, to help correct severe in-toeing. It's just one of those stories that sort of sticks with you, not unlike The Poky Little Puppy.