I believe that kids have a way of becoming whatever they are going to become, in spite of their parents, and therefore, it is possible (although not very likely) that your offspring will be the complete opposite of you in all sorts of ways, possibly to your complete horror.
That's the premise of Brian's joke that Zelma will grow up to be a *soccer-playing **horse-loving ***lumberjack. In some distant future, so he claims, Zelma will be driving one of those massive tree killing bulldozers through an old growth forest, while I stand resolute in front of her, waving my "save the trees!" sign in protest. Zelma, snazzy in her lumberjack flannels, yells out in her gruff voice, "It's progress, Ma! Move out of the way!" revving the engine as I beg for her mercy. ****Brian will meet her later for soccer practice and a horse ride.
* I dislike soccer
** I dislike horses
*** I love for trees to be left where they are growing
****This is all, of course, complete silliness, because by the time Zelma grows up, either,
A. (As I hope) everyone will have come over to my point of view, and no one will cut down any trees anymore,
or, (as Brian sees it)
B. There will be no trees left to cut down.