When faced with a situation that needs an explanation or a solution we tend to opt for the easiest answer we can come up with. Often, the result is not much use, and it can even makes the problem worse.
This is because it is easier for us to make assumptions, than it is to think things through. Assumptions are like ready-made thoughts. They pop into our minds, conveniently saving us the trouble of sifting the evidence or looking further.
If there are two explanations for an event, then the simpler one is usually better, the more assumptions you have to make, the more unlikely an explanation is. ‘Obvious’ answers often rely on speculations, guesses, unchecked assumptions or inherited beliefs.
Next time you are faced with a problem, as the simplest answer is likely to be the best one, look for the explanation that is the most likely given the facts, not the one that makes complicated assumptions.
William of Occam came up with this is the fourteenth century, see Occam’s Razor