What is the Dunning–Kruger effect?

The less competent someone is at something, the more likely they are to overestimate their ability — because the skills needed to do a task well are the same skills needed to judge how well you're doing it.

The mechanism is a double burden: incompetence produces wrong answers and strips away the ability to recognise them as wrong. A beginner literally lacks the knowledge that would reveal the gaps in their knowledge, so they feel confident. Genuine experts, by contrast, are acutely aware of what they don't know and often under-rate themselves.

Example: Someone who has watched a few cooking videos may feel ready to run a restaurant kitchen, while a trained chef is painfully aware of how much skill the job actually demands.

Tip: "The first rule of the Dunning–Kruger club is you don't know you're in the Dunning–Kruger club." Feeling certain is not evidence of competence.