Wait, how would Dyslexia not allow you to notice that?
If that was about my revelation about my "thair" friend, I don't understand the question about it. He was(/is) dyslexic, although nobody (who mattered) knew about dyslexia back when we were both at school. His spelling was universally awful
probably because of the dyslexia making it impossible (unaided) to learn, and thus the use of "thair" did not stand out as a peculiarity to third-parties. (I actually don't know what it looked like to
him, but he was very consistent with that particular 'writo', so maybe it was a pattern of letters that clicked, or that combination was capable of bashing its way through the wall of obfuscation that the dyslexia caused, and so was taken as a 'bedrock' word that didn't suffer quite as much as its correctly-spelt semi-phonetically similar siblings.)
All this has as a background that he was pretty much 'streamed' in the lower set of classes (full of the... not mentally tip-top people, plus disruptive and awkward pupils who may or may not have been that way
because they were not the smartest and/or suffering from similar undiagnosed learning impediments and were thus playing to type) and yet I consider him to be
at least my equal (I was in the 'top-end' classes, but actually didn't fulfil my potential[1]), if not far cleverer. Certainly socially more capable. (For one thing, he doesn't go around claiming he's more intelligent than other people!) But back then he was just another "awkward one", whether anyone considered it a wilful awkwardness or not.
[1] In a couple of cases because I may have been bored by what was being taught, and in others because I was the put-upon 'swot' and thus disrupted by bad elements, but neither of these things can I consider to be anything more than
excuses... The point is that I think I'm pretty intelligent, and I think he's
more so, but was hindered more than me. These days (if we were young again) he'd have got a
lot more help and who knows where that would have gotten him! As it was he's since become a published author. Not to great acclaim, but it's certainly more than I've done... And I was the initial proof-reader of two of the books (or certainly
one of the initial proof-readers, when it was still at the 'family and friends' stage), as well as long-term friend throughout school, so I'm fairly confident of the salient facts on this one. But I think I digress.