Take a deep breath...

You are lying down. You can't move. Your arms are locked beside you, your legs stretched out, unable to make the slightest change in position. You cannot move any of your limbs, your trunk or your head. With all the strength you can muster, you force your eyelids open. You stare upwards, and notice a clock, ticking away the seconds. You can hear the clock's hand moving, but nothing else. You still can't move. Your eyes are fixed in their gaze at the clock's face. You realize that there are no hour or minute hands on the clock. There are also no numbers on the dial, no visible marks or symbols. There is only a slender hand that ticks away the seconds. This can't be real, you tell yourself. This has to be a dream. And yes, it is a dream, but not your own. You are stuck staring vacantly at the face of a clock with a single hand counting down the seconds and it is all taking place inside a stranger's dream. And the stranger does not know you are there, unable to move and staring at a clock in a distant corner of their dream. This will go away, you tell yourself. Every dream has to end at some point, even if it is an unseen stranger's. You decide to close your eyes and wait while this passes. Your eyelids don't budge. The seconds keep passing. You feel a strong itch in your left foot. The seconds appear to pass even slower. You realize that you have been holding your breath since you opened your eyes. You try to exhale, but you can't complete the effort. Your chest feels ready to explode. And just when you are about to resign yourself to your fate, you think you see a thread of hope, hanging right above your face. Of course, the thread ends millimeters above your nose and dangling at the end is a hairy spider. You feel the urge to sneeze. You can't.

Posting this was a mistake.

In any endeavor—and in life in general—there are three kinds of mistakes.
The huge mistake is the most obvious one. Once you realize you've made one, there is no going back. You have to take the fall and hope you can rise again another day, if there is another day.
The medium-sized mistakes are easier to notice. And while you usually feel stupid about making these, you can usually fix them as soon as you find them, meaning you wasted a bit of time or effort, but it didn't matter much in the long run. These are the mistakes you usually "learn from."
The final kind are the teeny-tiny itsy-bitsy mistakes. You can't notice an individual mistake of this kind, except when it is committed by someone else. And since you don't notice them individually, they can accumulate. And accumulate they often do, creating a slow and gradual downward trajectory of microscopic failures which do not seem to have any identifiable origin.

Probably not to scale.

The third kind of mistake are often the ones that doom projects, people and even entire civilizations. However, people like to blame the huge mistakes, even when there are none, even if it means calling a medium-sized mistake a huge one.