Destroy the Object

I'm tempted to use Unity3d as an interview tool for intern/new grad candidates as a great example of the dangers of not getting rid of your objects.  It was cool to see it hang on to shot objects forever because they never ran into a border which would de-instantiate them. Why are interview candidates not infinitely smart compared to me when I was looking for a job?  Seriously - with tools like this, you should be able to talk for hours.  And hours.