Why all of the messes?

Here's my question -- Which of us passed along the gene that causes my children to take a perfectly clean room, & in less than 5 minutes, turn it into an absolute disaster zone??  I still can't understand why a room that looks like this is more fun to play in than let's say a CLEAN room, but I'm guessing my wonderful little angels have somehow found this life truth that I have somehow managed to go through life without. 

Apparently devices built to hold toys are also able to double as equipment generally found on a playground...