Do Native English Speakers Make Mistakes?

Last night my son needed a hand with an English essay he was writing about the different kinds of engineering careers that exist. As I was helping him, typing out some of his ideas since I'm a fast typist, I accidentally misspelled some words, which caused the word processor to underline the errors with squiggly lines. "Wow, Dad, you make spelling errors, too," my son said, wide-eyed. "I didn't know native speakers could make mistakes with English." This is a common believe among Japanese people: that every bit of English a native speaker produces in spoken or written form will be totally correct. When I was working as an ESL teacher, I made darned sure to prepare for my lessons, since not being able to answer a question about a certain type of grammar from a student is really hard on a teacher's ego. The Japanese also assume that I know every English word ever coined, and whenever I go see a doctor he'll usually explain in the most esoteric of medical terms what's wrong with me, then look a little sad when he sees my uncomprehending face.

Even monkeys fall from tree. Even gaijin mis-spell misspell words.