Sherlock was just minding his own business, laying down on the lost in his thoughts when suddenly the doorbell rings.

It's not a client, he can tell, he gets up to open the door, lazily, he'd rather stay on the couch. When he opens up he sees that the person in front of him looks rather familiar. They have quite a few similarities to Watson

"Who are you supposed to be?”

He asks, raising his eyebrows as he looks down at them

"I'm looking for John Watson... I was told he lives here?”