Lovely! Sentiment, in all the uncomfortable and awkward ways that it comes with Sherlock. John can only handle him so much, but it's good of him to be there to help Sherlock handle himself.

I love the idea that Sherlock had a teacher who especially liked him, even if he didn't quite realize it at the time. (I wondered if any of my former students would come to my showing or funeral, but that's a bit maudlin. Better take my hat.)

I can only imagine that Mary was relieved to go venue hunting with Sherlock's notes but without the men-folk. I loved how she got rid of both John and Sherlock by telling them the other needed to get out!

I also love John's deductions about the paper, and I can totally see how he'd tease Sherlock and then feel like a jerk.

Well done!