This was the consultant's opening gambit in a tutorial about dementia. We went on to discuss this idea and noted characteristic observations of an elderly dementing driver at an intersection,and the differences compared inexperienced drivers.

Younger drivers usually have superior reaction times, their mental processing can usually identify risks. However, inexperienced drivers may respond somewhat inappropriately to the perceived risk, resulting in "close calls" and situations that could well be described as a "lack of judgment".

A kid getting their license for the first time is excited; they feel great, and are often lauded by their peers and parents alike. They have achieved a new level of independence, and are becoming a fully functioning adult.

Conversely, dementing drivers have markedly slowed reaction times, and their mental processing is overwhelmed by the mass of information. Their inability to integrate large amounts of complex information in a very short space of time, and act accordingly, is the crux of the problem. The medical term is "executive function"; in dementia it is compromised.

Often though, the demented driver has some coping mechanisms in place. They may hesitate before selecting a gap, may stay close to home and avoid highways. Taking a license away from this person will leave them trapped and house-bound. They may feel demeaned and wronged, because they've never had a crash in their life. Their independence will be curtailed, and their outlook on their life may suffer.

Additionally, driving delirious or drunk is a bit like practicing medicine drunk; you put others at huge risk unnecessarily due to the short-term compromise in your executive functioning. Simply put, if you drink and drive, you're a bloody idiot.

These principles seem to echo into medicine;

We celebrate getting our license, we don't work or drive drunk and we're aware that as we get older, whilst our coping mechanisms and experience grow sharper, at the end of our careers our processing skills and executive function may diminish.

Then what? Do we continue to practice? Do we wait for the proverbial 'tap on the shoulder' from authorities? Or do we wait for an ambulance to pick up the pieces of our accident?