One of my most memorable moments from medical school was during my rotation in a psychiatric hospital. Unlike traditional medicine, you’re unlikely to figure out what is going on by sticking the patient with needles. Instead you learn to listen for inconsistencies that might indicate a delusion or hallucination.

On one occasion, I was taking a medical history from a well-kept man on a psychiatric ward who wouldn’t have looked out of place in a law firm or investment bank. That was until he started to describe, in all seriousness, that “agents” had been tailing him for weeks. Apparently, he had been assigned a top secret mission to penetrate a cult and was on the verge of uncovering a major conspiracy.

While delusions of this kind sound impressive, it wouldn’t be unusual to hear similarly grandiose stories from a startup founder.

Self-confidence to the point of delusional seems to be a common trait amongst successful founders. Later stage founders often admit to having no idea what they were getting themselves into when they first started their company.