Typos are an integral part of using a keyboard. I remember when I was at the peak of my typing performance and managed to do 96 wpm (words per minutes) with 3 errors on an IBM Selectric typewriter a long, long time ago. Correcting mistakes back then was a real pain, requiring in the REALLY old day, erasing them and hoping not to create a hole in the paper in the process, or white-out, which looked pretty tacky. Thank heaven those days are over! I remember having to retype pages and pages of manuscript due to some minor edits that changed the pagination. Yuck!
Since the advent of word processors, correcting errors has become a piece of cake. That makes it even more inexcusable not to do so. Typos really annoy readers, but they’re even more inevitable than they were in the old days because now there is less incentive to be precise than that funny, pink, circular eraser with the brush on one end or that little bottle.
Be aware of the ones you repeat most often. Transposing letters is tough to catch, but everyone probably has words they repeatedly misspell. I wish I have $1 for every time I typed “you” instead of “your”. I also tend to type “the” instead of “that” or “then”. When you’re aware of which ones you tend to mess up, you can usually make a quick check as you write or finish a given sentence to make sure it’s correct. These type of typos that a spellchecker won’t catch can really be a challenge, but trust me when I say your readers will indeed catch them. Hopefully your proofreader or editor will.