dunning-kruger effect
Vicky Zhao indirectly frames the answer for "why have a zettelkasten?", especially for learning, as overcoming the "illusion of competence" which is closely related to the mere-exposure effect and the Dunning–Kruger effect.
And asking them if they think they know what they are doing will not help, because many people will overestimate their knowledge, making the support even more complicated as the tech guy may at first believe them and only find out later that they told wrong things because they do not actually know what they are pretending to know.
Gignac, G. E., & Zajenkowski, M. (2020). The Dunning-Kruger effect is (mostly) a statistical artefact: Valid approaches to testing the hypothesis with individual differences data. Intelligence, 80, 101449. https://doi.org/10.1016/j.intell.2020.101449
Dunning–Kruger effect is a cognitive bias in which low-ability individuals suffer from illusory superiority, mistakenly assessing their ability as much higher than it really is.
Never knew that it had a name...