"Sherlock, what's your Chinese sign?" John suddenly remember to ask him while having his Chinese takeaway.
"John why can't you just think? Surely you have heard of the word "deduction" since you are living with the world's only consulting detective." Sherlock is trying to put his dumplings into a smiley face just like the one on the wall.
John puts his I-am-trying-very-hard-to-deduce face on and suddenly shot:" I got it! You must be a horse!"
Sherlock pauses and sighs heavenly :" Listen John, you cannot judge ones' sign by the length of their face!"