Aerodynamically, the bumblebee shouldn’t be able to fly, but the bumblebee doesn’t know that so it goes on flying anyway.

The saying uses the bumblebee as a parable about self-limiting beliefs: if you accept “expert” pronouncements about what is possible, you may never attempt what you could in fact accomplish. Its force comes from contrasting external calculations (“shouldn’t be able to fly”) with the creature’s untroubled persistence (“doesn’t know that”). In motivational contexts—especially business and self-help—it encourages action in the face of discouragement, skepticism, or intimidating theory. Notably, the “bumblebee can’t fly” premise is itself a popular myth based on oversimplified early aerodynamic assumptions, which ironically reinforces the quote’s theme about the fallibility of received wisdom.

1) “According to all known laws of aviation, there is no way a bee should be able to fly… The bee, of course, flies anyway.”
2) “The bumblebee is not supposed to be able to fly, but it doesn’t know that, so it flies.”
3) “Aerodynamically, a bee shouldn’t be able to fly, but it flies anyway because it doesn’t know it can’t.”