If there’s one creature from Japanese folklore closely tied to martial arts, it’s the tengu. Dressed like a yamabushi, the mountain ascetic warrior, it is usually depicted in two forms:

· Karasu tengu: literally “crow tengu.” Half-man, half-crow, often less powerful and subordinate to the daitengu.

· Daitengu: more human-looking than the karasu tengu, often with red skin and a very long nose. The most famous example is Sojobo, who taught martial arts to the young hero Minamoto Yoshitsune.

In Japanese folklore, tengu can teach secret martial knowledge to practitioners who train in the mountains. They were often painted in makimono (scrolls) of ancient martial arts schools.

Sometimes portrayed as protective mountain deities, sometimes as cruel troublemaking demons, all tengu seem to share one flaw: arrogance. In Japan, the expression “Tengu ni naru” (to become a tengu) refers to someone with an inflated ego. Likewise, when a character’s nose grows in a manga or anime, it doesn’t mean they’re lying like our Western Pinocchio, but that they’re swelling with pride or arrogance. And few flaws are as damaging in martial arts as arrogance and self-importance.

The Already-Filled Vessel and the Endless Path
In martial arts, learning never stops. It’s a path of infinite progression. To grow, one must have both the mental space to acquire new knowledge and the humility to relearn things when necessary.

Progress requires, above all, the humility to admit one can improve. Unfortunately, it’s very easy to do the opposite.

In the study of human cognitive mechanisms, we often refer to the Dunning-Kruger effect, named after the two American psychologists who discovered it. Also called the overconfidence effect, its principle is simple: less skilled individuals tend to overestimate their abilities, while more skilled individuals underestimate theirs. It’s a phenomenon we often observe: someone gains a bit more skill than the average person, and suddenly their ego takes flight. The beginner first climbs the “mountain of ignorance,” only to be confronted at its summit with the extent of all that he still has to learn, and then descends into the “valley of humility.” Their confidence may rise again, but under the watchful eye of more realistic self-assessment.

But as mentioned, martial arts learning never ends. Even an expert can suffer from the Dunning-Kruger effect and is not exempt from questioning themselves and their practice, and contemplating the extent of their own ignorance. Socrates, despite his vast knowledge, said, “I know that I know nothing.” Yet some experts are like vessels already filled to the brim with knowledge—or so they believe. But self-importance comes at a high cost in martial arts. In recent years, we’ve seen overly confident Asian masters quickly defeated by athletes from more practical styles, while other traditional but wiser and humbler experts manage to hold their own and earn respect.

Martial arts are wonderful tools for building self-confidence, but they can also inflate the ego and create false certainties. Stay humble, keep the beginner’s mind (Shoshin (初心)), and you will only improve. Become an arrogant tengu, and one day your long nose will break against the wall of reality.