3.1 That time is always when you least expect it. If nothing can go wrong, something will. Nothing is as easy as it looks. Everything takes longer than you think. Left to themselves, things always go from bad to worse.
Nature always sides with the hidden flaw.
Given the most inappropriate time for something to go wrong, that's when it will occur. Mother Nature is a bitch. The universe is not indifferent to intelligence, it is actively hostile to it. If everything seems to be going well, you have obviously overlooked something. If in any problem you find yourself doing an immense amount of work, the answer can be obtained by simple inspection.