One of the movies that we picked up at the library is one that has become a favorite of my son.
A couple of years ago, I checked out "October Sky" from the library, and pretty much forced my son to watch it. He loved it. We've checked out this movie more than any other movie, and by all rights, we should just buy it. The reason I don't is because I don't want him to watch it over and over, for fear he'd get bored with it. It isn't often on the shelves when we look for it, so on those rare occasions when we find it, it's that much more of a treat.
We just finished watching it again, and he has new enthusiasm for rocketry. While my son's interests have shifted once again, from wanting to be a paleontologist and and an astronaut, to being a paleontologist and a geologist, he's still very interested in space, rocketry, and the machines that get us into space. Someday, those interests may be complimentary.
Until then, he'll build his spaceships out of Lego blocks, and bits of scrap wood, and draw his battle scenes and aliens on paper. And some day, in the future, he'll tell a group of kids how he got started...