Lights On, Lights Off

This morning it is partly cloudy. It is so nice out that I have all the windows open letting some fresh air in! All morning though Bryce has been talking about the lights going on and off. We sat down to eat lunch together, and I finally figured out what he was talking about. When the sun went behind the clouds he would say the light went off and when the sun came out he would say the light is on. I explained it was the sun and the sun provided light and warmth, but he is 2. We will see how much he understood at some point. The only response I got was "light on!"