The tale behind the proverb goes:
“Once upon a time there was a frog who spent all his life in the bottom of a Well. This frog was very content with life: he enjoyed hopping around his beautiful dark home; he was never short of insects to eat; and he had water to swim in. What more could he ask for? The frog could think of nothing he missed and when he looked around he saw no other animal with so much comfort and wealth as he had. He was the happiest frog, living in the best place in the world! Or so he thought.
One day, when the frog was gorging himself on insects and listening to the echoes of his happy croaks, another frog from the outside world fell into the Well. The new frog looked around the well, croaked and began jumping as high as she could to get out of the well. Surprised by the new frog’s eagerness to exit the well, our happy frog hopped beside the new frog and told her she should stay in the well because she would never find another place as wonderful as this well.
The new frog stopped jumping and came to rest beside the happy frog. Then she spoke of the many ponds and water lilies in the world outside of the well. She told the happy frog that he looked skinny and pale. Our happy frog then knew that all he thought he knew was wrong.”