I'm no Sherlock Holmes
angry doc: … and you should stop smoking too.
Patient: But I don’t smoke!
angry doc: (annoyed) Then what’s that in your shirt pocket?
(Points at cigarette packet in patient’s shirt pocket.)
Patient: This? I only use it to hold my keys. See?
(Produces keys from otherwise empty cigarette packet.)
angry doc: … OK, let’s talk about your diet now…