LOL Kids do this into college. Right now they are building LEGO MINDSTORMS robots to go up in the next Atmospheric balloon launch in AZ in the Fall. All sorts of things there - how to survive the pressure, how to survive the fall, what will the NXT be measuring etc. A few of the adults at the NXTSTEP blog don't have kids!

We do tend to go in phases like any toy....we pick it up hot and heavy, then move on to something else, then pick it up again. That's why I wanted to do the LEGO Mars Base Command mission - to give us something targeted to do.