I came across an interesting optical illusion called Ames Window. Watch it here:
This shows how the optical illusion fools our brain even though we know that the reality is different.
This is a very good example to keep in mind, because our brains are really susceptible to make such mistakes, and this is true for all aspects of life and all domains.
This reminded me of Richard Feynman’s First Principle (and warning for all of us):