The perfect coloring medium

Why did it take so long for toy companies to perfect coloring with water? Shouldn't this technology have had greater importance than say, landing on the moon? The water color books we had as kids got colored water everywhere. This new technology is great! (As long as you don't misplace the water pen.) That's a stamp from gymnastics on her hand in the first picture, not a stain from coloring with water. It must be my practice with pictures in clouds that leads me to see so many things in Hazel's scribbling. In the second picture I see a chickee, a flamingo and a running man with sword and shield in hand. And this particular drawing board also taught me to draw a doggie and a butterfly - never too old to learn new things.