As I watched this video play back before I posted it, I was struck by how different Matthew is from his older brother. At this age, Ethan was stacking blocks, but if they fell down or didn't stack how he wanted them he would get extremely frustrated to the point of tears. Matthew is happy just to stack and re-stack until he achieves his goal. Funnily enough, the goal is the same between the two boys -- to knock down whatever they build with great gusto!