“Aerodynamically, the bumble bee shouldn't be able to fly, but the bumble bee doesn't know it so it goes on flying anyway.” ― Mary Kay Ash
I love challenging postures, like flying pigeon — Eka Pada Galavasana — because they require focus, attention and a big dose of grit and power.
But mostly, because a posture like this blends effort (engage!) and ease (relax!) in perfect balance & harmony.
More on this posture? Here's a great article by Yoga Journal: Eka Pada Galavasana.