You said:

"I don’t see the argument for spell-checkers being responsible for a perceived decrease in spelling ability, because a spell-checker is merely an electronic dictionary. Instead of spending time pulling a tome off of the shelf and looking up a word, you do it more efficiently by using a computer, and you get the same result. Whether you then take the opportunity to commit the correct spelling of a word to memory is up to you, regardless of whether you saw the correct spelling in a physical dictionary or in your word processor’s dictionary"

That's a great point.

I was referring to words I know and know well.

Maybe I am not too bright and getting duller by the moment is an explanation. However, I was an okay/decent speller as a kid and it was as a kid that I developed certain practices and methods that caused me to do well in exams and the like.

I am not blaming my computer for this sudden deterioration. Nor am I seeking excuses for geting stupid. However, a good few people I know and who are not utterly stupid, have noticed something similar.

My own take is that my typing is so quick that I am, almost, verbalising stuff. Unfortunately, my rapid typing is often of poor quality and I am not going through routines that were once embedded in me after hours of learning, to spell those words. I am quite simply out of practice.

Perhaps, I also rattle off "shit" because I am disengaged from the subject I am typing about.