There are easily hundreds of posts on the interwebs dedicated to reminding people the differences between "their" vs "there" vs "they're" and "your" vs "you're." Not to mention all the posts reminding people that "a lot" is two words and "irregardless" has never been a word. (You should check out Hyperbole & a Half's post about "alot" because it's funny.)
Today I am going to share with you a personal grammatical struggle of mine that makes no sense. I often write things that sound similar to what I want to say (like that one time I wrote "fart sailing" instead of "start failing" and when I caught in edits, I laughed for like twenty minutes).
One that I've done more than once - in hand written notes and outlines, so there's no possible excuse for autocorrect mucking things up - is I write the word "machine" instead of "mission." Like, "She has to leave on an important machine." Some machines are important, I suppose, but that's not what I was going for.
Now, I know the difference. Verbally, I've never once said, "Hey, let's watch 'Machine: Impossible' starring Tom Cruise" or "I'm going to go throw some laundry in the washing mission."
So I don't understand why my hands don't know what my brain does. But I should really come up with some fancy memes for myself to put up to remind myself of the difference.