How did he get so smart?

This summer, to keep the house clean, we have required everyone to do their jobs before they can eat breakfast.  It has worked great as far as I am concerned.  The kids not so much.  We get some resistance, but most of them just do it without complaining.  Yea!  Our floors have been clean every morning:

This morning I slept late and J came in asking for breakfast.  I told him that I would help him sweep the hall and entry and then he could have breakfast.  He said, " I want a cheese sandwich."  I repeated that he needed to do his job and then he could eat breakfast, to which he replied, "That is lunch."

How did he get so smart?

H has become a pretty good sweeper for 4 years old.