Phrases like this one are optical illusions as our brain is quick to skip the second "the" only reading it once like we just did. It's also like reading a sentence with certain letters in a word scrambled up, but the first and last letter has tobe in the right place., but your mind reads them even if they are not there.
Don't think about this sentence below, it just read it.
it deosn't mttaer in waht oredr the ltteers in a wrod are, the olny iprmoetnt tihng is taht the frist and lsat ltteer be at the rghit pclae.
This drove spell-check crazy, LOL.