I just call those words RAS words. RAS stands for Reticular Activating System, which is a medical term for "I never noticed it before, but now that you point it out, it's everywhere!"

OK, that's not truly the definition, but it is a fairly accurate description of what's going on. Your RAS actually filters out the repetitive stimuli to prevent overload, but once something stands out for whatever reason, it overrides the RAS so you notice that particular stimuli all the time. It was always there, now it gets through the filters.

This happens with images, people, things and words, as well as parts of words. I don't know when I noticed this one particular words' spelling, but once I did, I do a doubletake every time I see it, and mentally spell it every time I hear it! The word is "Lincoln," which, up until about 10 years ago, I never noticed the second 'l' and probably would have spelled it "Lincon." Which, of course, is wrong and looks funny, but when I first consciously noticed the second 'l' I thought IT looked funny! Go figure!