Why do we sometimes say a word or look at a word so many times that it sounds foreign/doesn’t look like a real word?

Question

I hope this makes sense

Like when you’re taking notes and you write a word and it just doesn’t seem spelled correctly no matter what or it just seems strange, or when you say a word and it feels weird coming out and you have difficulty comprehending that it’s an actual word.

In: Other

Answer 1

I do this with the expression “how come?”. A question asked very frequently yet if you look at it for long enough starts to look weird and I wonder why these two words together mean what they mean??