Everyone knows already what the Imposter Syndrome is (a quick google search shows 6.100.000 results), not so many know its counterpart: the Dunning–Kruger effect ( only 62.900 results).
If the Imposter Syndrome that affects many of us is a constant feeling of being not worth it ( the fame, the title, the money) because - despite the efforts and the results and the proven competence - we feel that
there is so much that we don´t know,
we are not those experts we pretend to be,
we are not so good as our colleague - or our boss, think we are,
the Dunning Krueger Effect is exactly the opposite: the overconfidence of people that have no freaking clue of what they are doing...
In a more scientific ( and wikipedic wording) the Dunning Krueger Effect is a cognitive bias in which people assess their cognitive ability as greater than it is.
Since you don´t have the meta-competencies necessary to evaluate your competences, you are therefore unable to recognize your lack of ability.
How many times have you heard someone in your team state that something was easy and could be done quickly, while you knew behind that "simple" requirement there was a hell of a lot of pain and hassle?
It is acceptable when it comes to interns and trainees or juniors, it is definitely annoying when it comes out of the mouth of some pleasing senior or project manager. Still, it´s a natural process in the development of us software engineers.
Of course, this is particularly annoying when this unawareness comes with a touch of arrogance.
My dad used to have a painting in his living room which I loved. With very fancy antique calligraphy it stated:
Four men are gathered:
One knows nothing, and he doesn´t know he knows nothing. He´s a mad man. Stay away from him.
One knows nothing, but he knows that he knows nothing. He is ignorant, teach him (help him learn).
One knows but he does not know what he knows. He is asleep, awake him.
One knows, and he knows what he knows. He is a wise man, follow him.
Since I was a kid these words resound in my head.
It does not matter at whatever stage of your personal and professional growth you are, or whatever people surround you: