As someone who never learned to type properly, I commit my fair share of typos. And I'm not the only one.
I think the arrival of word processors has highlighted the abundance of typos because people who would have simply written a note years ago now send an email. Thus folks like me, who don't type well, make lots of mistakes. And of course the whole texting thing has made it even worse as people shorten and change words to make it as quick and easy as possible to communicate.
I find that even when I read and re-read things, I still make mistakes. I suppose that has to do with the fact that I know what I mean to say and my mind sees what it thinks is there. I always read over my blogs before I publish them and yet when I read it after its published I often go back and edit mistakes.
Perhaps someday we will just speak into our computers and the machines can type ever word, mistake free and typo-less. It would be a dream for me.