A delusion starts like any other idea, as an egg. A delusion is an idea and that idea can be contagious. Humans are pattern-seeking animals which means we prefer ideas that fit a pattern. In other words, we don’t believe what we see; we see what we believe. But when we’re stressed or our beliefs are challenged, when we feel threatened, the ideas we have can become irrational, one delusion into another and another, as the human mind struggles to maintain its identity. And when this occurs, what starts as an egg can become a monster.