If you’ve seen these Muller-Lyer Lines before you know they’re the same length. If you haven’t, go ahead and measure; I’ll wait.
Our eyes are tricked by the accompanying angles. Once we know this, our minds can overrule appearance and believe reality. But this takes prior knowledge and a conscious effort to apply it.
So it is in life. When things happen, we immediately perceive them in a certain context. We put our brackets on events, superimpose our ideas onto facts, add our adjectives to nouns. We can’t help it; it’s intuitive.
Here’s the interesting question: Where did you get your angle?