you know what i noticed?
sherlock is *less* rude to his father than he is to his mother.
when mummy displayed the slightest bit of affection for sherlock (in the form of a caress to the cheek) he immediately sought to remove himself from the interaction, as opposed to when his father displayed affection through his concern for Sherlock’s friends, sherlock simply acknowledges daddy’s sentiment without so much as a second thought.
this observation leads me to believe that sherlock may have spent more time around his father as opposed to his mother, alluding to how he ought to interact with the world given that his father seems to lack social skills as well.
just a thought
it could also lend to the fact that, when his mother was giving affection, it was to him, both times that we see her do it — the one time at 221B and the second time when she threatens to become “absolutely monstrous” towards whomever shot him. But when it’s Sherlock’s father, he’s giving concern to Sherlock’s friends, to John and to Mary, to people that he connects with and relates to. He cares about them, and so anyone who reflects that care towards them, he will accept the sentiment because he feels it too
Now I’m just imagining the Holmeses as young parents:
Mummy - genius, but not very good with kids, so she reads tons of parenting books because she really wants to do a good job (no matter how often Daddy Holmes tells her she’ll do just fine), and the books say that if a child isn’t shown affection by their mother, it gives them all sort of complexes, so she makes a deliberate effort to be affectionate to her children every day…even though she’s a bit rubbish at it, she keeps trying because she believes it’s important.
Whereas, Daddy Holmes simply notices that Sherlock doesn’t like physical affection (witness his cringe when Angelo grabs and hugs him in the restaurant), so he shows his love by verbal compliments instead. (“Well done, Sherlock.” “How extraordinary. Did you do that all by yourself?”)
What I think is even more interesting is how this plays itself out when Sherlock grows up. I reckon Sherlock is much more like his mum temperamentally, which we can see in his awkwardness when Archie and Anderson hug him: “OMG physical contact is expected of me in this situation I have to do something there I patted them that counts right?”
Whereas John, upon hearing Sherlock’s deducing skills for the very first time, responds with a verbal compliment, exactly like Daddy Holmes: “that’s extraordinary.” And Sherlock lights up like a candle.