What was my brain doing at 4am?
Um, pondering that 'sir' is a good gender-free honorific given that it's derived from sire, which is used for monarchs of any gender--essentially, "you're like royalty to me"--while any masculine tone it has comes from the British monarchy's primogeniture rules, which don't really apply here, but set up a subversive sense of both 'you deserve all the privilege given to men in society' while evoking the dichotomy of...
Wait, why? What was YOURS doing at 4am?