I agree with all but the last one. From my experience, I'm the only one NOT noticing how anyone writes while I get "oh, you're left-handed" constantly.

But the smudging part reminded me of something that happened to me:

I had a maths teacher who always had one of us do the homework on one of those overhead projector foil things and show them in front of class. I had a geometry task and would always smear the rewritable pen with my palms, or mess the lines up because I had to hold my hand awkwardly high. He did make me do it over and over again because he thought it was sloppy. My mum tried to talk to the teacher and the principal, that I as a lefty kind of faced an uphill battle there, so having me re-do it when I wasn't able to do it the first time was not really going anywhere. The teacher only told her that I needed to learn ways around my left-handedness. So my mum had me do the homework with a permanent marker. No smearing anymore. The teacher even had a smug face on and was all like "See? You can do it after all". That smugness was gone when he tried to clean up the foil. No one said that he had to like the ways I found to deal with such BS.