It's a well trotted-out joke by some of my colleagues that whenever you go to Nottingham Playhouse you need to take your brain with you. That's because the theatre specialises in bold, innovative drama which makes you think.
So imagine the reaction when they heard the Playhouse was putting on The Man Who which looks into the complexities of the brain and how it works.
Artistic director Giles Croft is gaining quite a reputation for staging rarely performed works. In the four years since being appointed to the job he's directed Robert Lepage's Polygraph as well as four world premieres. More are in the pipeline.
Now he has become the first director to tackle The Man Who since Peter Brook staged it in 1994.
Nine years before that Oliver Sacks, described as "the poet laureate of medicine", had produced a book called The Man Who Mistook His Wife For A Hat, a series of case studies involving patients with neurological problems.
Brook turned it into a 17-scene theatrical piece with four actors switching from patients to doctors as they attempted to get into the minds of people suffering from conditions such as autism, agnosia, loss of proprioception, blindsight and Tourette's syndrome.
It's a good idea to arrive early for this production as it gives you time to read the programme and find out more about the disorders the patients are suffering from.
Croft's 85-minute production is played straight through without an interval. It attempts to provide insight into how our perception of the world can change when we're afflicted with a neurological condition which we may not realise we're suffering from.
The play raises a question which has been aired many times before: what actually constitutes entertainment?
Medical science can fall into that category and there were moments when the audience laughed out loud.
The intelligent patient who began arguing a point coherently only to come out with sentences of unrelated nonsense was particularly comical.
So too was the man with Tourette's, superbly played by Robin Harvey Edwards, who because of his tics was advised by a friend never to go to an auction! The audience also laughed at his outbursts when he couldn't prevent himself shouting and swearing.
The three other actors, Jonathan Oliver, Alan Perrin and Anthony Taylor, are all excellent whatever roles they assume on Helen Davies's simple set, which has a private hospital feel to it. The scenes are in turn instructional, touching and occasionally distressing, and only one appears to go on too long.
But the piece doesn't discuss how any of the patients come to be suffering from these conditions or whether the doctors can do anything to improve their existence. You sit in the audience feeling ineffectual, detached and powerless to help; you don't have the ability to do anything about their disability.
Perhaps this is why, as eye-opening and thought-provoking as the play is, it hasn't been performed since Brook originally did it.
"The Man Who" runs until October 18th