Its because I can just mash anywhere NEAR the letter I want to write, real fast over the keyboard, and it will analyze the general areas I mashed and think "okay, out of all possible words this buffoon could have been attempting to go for, I found three that makes sense to use in the context of this text, and its most likely this one he aims for, so Ill suggest that plus the other two".
And I just mash space and go on mashing and eventually the text is over and I look like god damn Hawthorne when I see its all correct and totally understandable.