Why does the the human brain ignore the second the?

Have you ever proof-read an essay 10 times before submitting it, but had an extra word pointed out to you? Why does the the brain sometimes ignore these extra words? Shouldn’t errors jump out to us because they’re an anomaly? Let’s get into it!

Sources:

[Saccades and Eye Movements]
https://link.springer.com/article/10....
https://www.ncbi.nlm.nih.gov/books/NB...
   • Saccades  
   • Corrective Saccades  
   • Smooth Pursuit  
   • Virtual showroom application. Screen recor...  
   • Vergence and Convergence Reaction Test  
   • Normal and Abnormal Eye Movements  

[Parafoveal Vision and Information Gathering]
https://www.sciencedirect.com/science...
[Word Skipping]
https://www.ncbi.nlm.nih.gov/pmc/arti...
https://www.ncbi.nlm.nih.gov/pmc/arti...
   • Видео  
   • Видео  
   • Видео  
[Other Sources]
   • World's tallest man meets world's shortest...  
https://media.giphy.com/media/z8rEcJ6...
https://media4.giphy.com/media/ZIG63R...
https://media.giphy.com/media/LNqJlnw...
   • Brain  
https://media.giphy.com/media/w6TfGhq...
https://media.giphy.com/media/13rQ7rr...
https://media.giphy.com/media/111ebon...
https://media.giphy.com/media/hCadYk8...
https://media0.giphy.com/media/lmftWb...
https://media.giphy.com/media/KxzKGZJ...
https://media.giphy.com/media/3orifcf...
https://media.giphy.com/media/581WiiN...
   • Amazing Cross Eye Stereogram  
   • Tales from the Prep Room: The Ames Room  
https://media.giphy.com/media/l3vRlk7...
https://media.giphy.com/media/qKltgF7...
https://media.giphy.com/media/3oz8xPy...

[Brew’s intro song]
Manhattan Twist by Avocado Junkie