I think I’ve got something in my eye.
What I love most about this is that, like always, he turns to John because he doesn’t understand.
'John, did I do it wrong?'
You can see the character development in this, too, and how much it means to Sherlock to get it right, because he doesn’t just say ‘Not good?’ he says ‘Did I do it /wrong/?’
Because it’s important to Sherlock that he gets it /right/ for John and Mary.
But legit yo this was my favourite part of the episode because Sherlock likely has something like Asperger’s, hence him not being able to ‘read’ the situation. But unlike some comedy shows that shall not be named, rather than making a joke of the situation like “Hah! See! No matter how hard Sherlock tries, he won’t be normal!"
John gives him a big ol’ hug and assures him that he did it right. He successfully interacted with a large group of humans. It made me smile hella hard.