All by Himself?

A child spends the day building a castle with wooden blocks, all by himself! But was it really only his work that made his masterpiece possible?

What does it take to create something new? A whole lot of work, and a whole lot of people! The child may be the one to stack the building blocks. But someone had to transport the blocks, and someone had to carve the blocks from wood, and someone had to plant the tree that provided the wood for the blocks, and so on!