system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How come when you start thinking about something while reading your eyes can continue reading but you actually have no idea what you just read?
gpt
tl;dr you weren't paying attention.

the long answer is that reading is more than just physically seeing characters on a page/screen, you have to decode those characters into words (which is usually an automatic process), decipher the meaning of those words and join the words together into an understood statement, of which the latter processes aren't taking place at all, because you're busy thinking about something else, same for when we're listening to someone speak but don't have a clue what they said, the hairs in our ears vibrated due to the sound the speaker made, but we weren't paying attention to what the actual meaning of those sounds meant.

this is also why you can not hear someone at first, but a split second later understand what they said, right when you were about to ask what they said, your brain finished processing those sounds into actual meaning because there's basically two levels of hearing, the first is completely automatic, the second is for when you don't subconsciously recognize a word, your subconscious hands it off to your conscious mind asking what it means.

I hope this made sense.