What's wrong with this situation? Sometimes it's the bleeding obvious. Other times, it's the smaller details. What makes us notice and register the oddness, jolting us, momentarily, from our exisiting line of thought or preoccupation...

Why do we notice the grubby child's handprint halfway up an escalator on the metal skirting?

Why notice the elderly lady in perfectly matching skirt, blouse and fabric trolley but no shoes?

Perhaps the junior doctor wearing two stethoscopes?

The teenager strolling around the supermarket with a recently chlorhexidine-ed foot?

Or the hundreds of medical students smiling, joking as they walk into an exam?