In my mother tongue, I have a perfect orthographical sense: I just need a glimpse of a word to know if the spelling is correct. As a result, proof-reading requires close to zero effort, and I do not use a spell checker for my mother tongue.
I type a lot in English, and I have come to realize that I do not have this same orthographical sense. Particularly, there are a lot of transparent words between English and my mother tongue with just subtle differences in the spelling, which makes me likely to spell them wrong — e.g. replace "n" by "nn" or "e" by "ea". So I usually have a spell checker on when I type in English.
Also, did you ask your students why they were shocked?
if I happen to use something with a spell checker I usually don't even notice it, and if I do I turn it off
now it's not that I never make typos, or I never make spelling mistakes. These happen all the time. The point is that I correct them when I read, and re-read, edit, and re-edit whatever I am working on (even a "simple" email)... using the spellchecker between my ears
It has the desirable side effect that I also am 'forced' to re-read what I've written, and inevitably, I change something, I hope to make it better
I think a lot of people have a workflow that goes something like this:
- hammer out some text - correct errors in real time based on spell checker flags - at the end, scan the document for spell checker colors; if none, then I am done!
I am a huge proponent of reading and re-reading whatever I am writing at least 5 times, and editing/changing as I go. I spot typos and spelling mistakes via this process.