That was my first reaction too. After thinking and discussing it with some non-technical people, though, I realize it's not a contradiction unless you also ass

That was my first reaction too. After thinking and discussing it with some non-technical people, though, I realize it's not a contradiction unless you also assume some physics knowledge. I (and probably you) have so deeply digested the fact that a pen and a heavy boot fall at the same rate that it seems like a logical failure to not incorporate it into a conclusion. It's quite possible that a person's understanding is simply inconsistent (at the frontiers of anyone's knowledge i think inconsistency is quite common; "learning" is largely a process of finding more data and working through implications to resolve them), but it not a foregone conclusion based on these answers. This is the main challenge in teaching people any technical subject - discovering the basic knowledge you have assimilated so deeply that you can't even imagine that others don't share it.