One thing’s for sure – Stephen Hawking is a very clever man. He’s known for his intelligence, his books, his theories, and – let’s be honest – for his survival instinct. When you hear it, everyone recognises that metallic artificial voice and knows about the motor neurone disease that changed a fit and able young man into a completely physically paralysed one. Personally, I can’t recall ever seeing a photograph of him as a young man, and I must admit that I’ve never thought about his private life at all. It’s as though his intelligence and disability are a mask that prevents us or discourages us from seeing – or even considering – the actual man underneath. My bad.

For that reason alone, The Theory of Everything is an extraordinary film because it lifts the lid on this private and unique individual and shows us the course of events that takes us from 1963 to the present day. It’s based on his first wife Jane Wilde Hawking’s memoirs so one can presume it’s all pretty accurate. We relive Stephen and Jane’s undergraduate days, their early married life together, the progress of both his career and his disease, their growing family, and the way they grow apart in the directions of Stephen’s helper/carer Elaine and their family friend Jonathan. In many respects it’s an ordinary family saga, just set against the background of a brilliant brain and a hideous wasting disease.

Mathematics and Science really are a foreign language to me. I haven’t tried to learn the basics of what Mr Hawking’s philosophy is about, because I know I simply wouldn’t be able to understand it. I know I wouldn’t grasp the concepts in his books. In the film I was entranced by the sequences when he is writing out his equations on a blackboard; reams and reams of hieroglyphics of which I couldn’t follow even 1%. They’re just patterns to me. So for me it was a revelation to relate these random, non-understandable concepts to a real man, his real hands writing the equations out on a real blackboard, flowing out from his real brain. It’s not just textbook theory – it’s Mr Hawking’s life-blood, full of passion, hope, and ambition. He wants to find the equation that proves the theory of everything. If that isn’t ambitious, I don’t know what is. Call me shallow, but it had never occurred to me that these (for want of a better word) sums actually stemmed from the mind of an individual person. I just took them as a given. I guess 1+1=2 was actually the brainchild of some caveman once upon a time.

Another aspect of the film that shows the human dimension of the man, rather than just singling out his brilliant brain, is the fact that people with disabilities are interested in sex too. This isn’t so much Does He Take Sugar? as Does He Use Condoms? – with the answer firmly in the negative. As the Hawking family continues to grow with more and more children – and Hawking’s disability seems to get worse and worse – I bet I wasn’t the only person in that cinema who thought “well just how the hell did he manage it?” That was also the suspicions of their contemporaries, as idle speculation from Jane’s parents and family wondered if Stephen really was the father of their third child – with suspicions alighting on their friend Jonathan. But no, Stephen is definitely the father, and it’s the mark of a classy film that they don’t feel the need to give us the ocular proof.

Visually it’s a stunning film, with lovely settings of Cambridge in the 60s as the backdrop to Stephen and Jane’s blossoming romance: the river, the university buildings, railings full of bikes, idyllic lawns. There’s a memorable scene where Hawking is led into a very old-fashioned looking laboratory by his professor in an attempt to galvanise him into some great thoughts and ambitions for his thesis. It actually reminded me of the Biology classroom at my old school, and it’s precisely the kind of place you would expect to see in a traditional institution like Cambridge.

But the really impressive heart of this film is in the acting. Eddie Redmayne delivers just about as perfect a performance as anyone could imagine as Stephen Hawking. From his faux-embarrassed brainboxy young undergraduate, to the world authority that he is today, Mr Redmayne captures a remarkable balance between expressing Mr Hawking’s character and portraying the physicality of his progressive disease. Over the course of the two hours you see Mr Redmayne literally deteriorate before your eyes in a way that you would have thought it was impossible to act – you would think he was genuinely suffering with the disease too. The strength of his voice also fades as the film continues, and somehow, facially, he even manages to recreate Mr Hawking’s trademark swollen lip; I guess that’s down to some clever make-up. His performance is clearly driven by sincerity and respect for the person he is representing; it’s a genuinely unbelievable piece of acting. I thought he was great as Marius in the film of Les Miserables – but this is a career-defining performance.

Felicity Jones plays Jane as a complete powerhouse of strength. The young undergraduate who spins around in joyful freedom by the side of the Cam when Hawking is trying to explain some cosmological law develops into the young woman who doesn’t flinch from the heavy demands of being married to someone with motor neurone disease. There’s one splendid scene where Miss Jones attempts to persevere with her own classical poetry studies, so easy to ignore as irrelevant compared with Hawking’s discoveries. There she sits, at a table, books spread everywhere, getting increasingly irritated that she can’t concentrate on the research that she wants because of family demands; but then she reassumes her role as wife and carer without comment or argument. It really conveys the challenges and stresses of her life. It’s a very thoughtful, honest performance; and also her growing fondness for Jonathan is portrayed with quiet respectability, decency and genuine affection.

I really enjoyed Harry Lloyd’s performance as Brian, Stephen’s university roommate and pal; bright, good-natured, funny, but supportive – the perfect credentials to be your best friend. The scene where Stephen tells him he is suffering from the disease and has two years to live is performed with utmost integrity. As the penny gradually drops, Mr Lloyd desperately faffs round trying to get his head around the fact that his friend won’t be around for long and that it will be a horrible death. Mr Redmayne meanwhile just calmly asks to be alone. It’s a perfectly acted scene. But Mr Lloyd gives great support throughout the whole film. There’s another dignified and mature performance from Charlie Cox as Jonathan, the choirmaster who helps both Stephen and Jane with the practicalities of life before slowly falling in love with Jane.

However, for me the film isn’t an unmitigated success, because despite enjoying it – and thinking the lead performance was simply remarkable – I have to admit that I got a little bored by it. As Stephen’s condition worsens, and the difficulties he faces increase, I found there was a general glumness about the whole film that rather wore me down; and the last half hour or so felt a little bland and lacked a dramatic intensity, primarily because we know that in real life, the real Stephen Hawking is still alive and kicking and slaying cosmological dragons.

I was also slightly irked that the film raises the question of Stephen only having two years to live, but never addresses the fact that this diagnosis was clearly wrong. Was the original doctor over-egging his pudding? Or is it an absolute miracle that Stephen Hawking is still alive? It’s a loose end I’d like tied up. I also felt the timescale was a little woolly throughout; it was hard to get a feel of the actual progression of years as the film went on. We know it started in 1963 but I couldn’t work out roughly what year any particular event might have taken place. Specifically I got confused by the car that Jonathan drives sometime after the third child has been born (when they go camping in France). It had a six digit number plate, meaning it was registered before 1963. But I believe we’re talking mid-80s when Hawking caught pneumonia in France. So either time had stood still, or Jonathan had a very old car.

Nevertheless, it is an excellent film that gives you an insight into the personal life of a very public figure, and it is crowned by a simply breathtaking performance by Eddie Redmayne. Highly recommended!