I mean, it's rather obvious it's just written down as it's spoken - like "bone apple tea". But while it's relatable that someone who doesn't know any French cannot write "bon appétit", I don't get how a native speaker could write "should of" and thinking yeah that makes complete sense.

It's also not an auto-correct problem like "there, they're, their" may have originated (I hope it did).

I understand to some extent, thanks!

i just learned yesterday that apparently america teaches kids to read not by, you know, having them read things, but by memorizing made-up rules to.. guess at how words are pronounced and what they mean..

this uh, explains a lot about why america is why it is, i feel.

shoulda makes vastly more sense, and is precisely the kind of thing that tends to become slang and eventually just the standard spelling, like "dunno" or "gotcha".

"should of" just feels like people know it should be two words, but don't know how it's spelled, and instead of just spelling it phonetically they make something half-phonetic up.