As humans, we are programmed to assume our solutions will work. It is an important evolutionary trait. The military solution to this optimism bias is to assert deductive reasoning and the arrangement of a reserve capacity, to compensate when systems fail, resources run out, or solutions are exhausted…..
Comment: The equivalent for investors, to maintaining a reserve capacity, is position-sizing: never bet so much on any one trade that an adverse outcome, or string of adverse outcomes, would affect your ability to keep investing/trading.