Skip to main content
Search IntMath

Born on a Blue Day - summary review

By Murray Bourne, 15 Apr 2009

Born on a Blue Day — Inside the Extraordinary Mind of an Autistic Savant — A Memoir by Daniel Tammet (Free Press, 2006)

Summary Review

born on a blue day

Daniel Tammet sees the number "1" as a very bright white, the number "11" is friendly, and "5" is loud like a clap of thunder. He has synesthesia, a condition that connects his senses together in a way that is as magical as it is rare.

According to Tammet, prime numbers (those that only have 2 factors, like 2, 3, 5, 7,...) are "smooth and pebble-like" while composite numbers (4, 6, 8, 9, ...) appear "jagged". My favorites — "39" is lumpy like custard and "89" reminds Tammet of falling snow.

There is much more to Tammet than his ability to see colors and shapes when he looks at numbers. He is an autistic savant. In particular, he was diagnosed with Asperger's Syndrome (or high functioning autism), which means he experiences many of the symptoms of autism but unlike most autistics, he is able to talk about his experiences.

Characteristics of autistic behavior include:

  • Repetitive, obsessive actions
  • Difficulties in social situations
  • Lacking empathy (and awareness) of others

Autism affects men more than women (80% of autistics are male).

Mathematical abilities

Tammet can mentally calculate values like 374 (which equals 1,874,161) and 13/97 to 100 decimal places (0.13402061855670103092783505154639...). (I featured a video of this here: The Rain Man in each of us).

He once recited the first 22514 digits of pi. This is more of a memory feat rather than a mathematical one, but he was helped in this task by the fact that he could "see" the colors and shapes of the numbers.

The book opens with an account of his fascination regarding his birth date: 31 Jan 1979. Each of the following numbers drawn from the digits in this date are primes: 31, 19, 179 and 1979.

His life story

What makes Born on a Blue Day extraordinary is the fact that Tammet had a very difficult education. He was bullied by his classmates because of his "weirdness" and compulsive behavior. He was socially withdrawn and preferred his own company. For Tammet, secondary school was a nightmare after the relative orderliness of primary school. It must have been a very difficult for Tammet and for his teachers.

But Tammet still learned despite his difficulties. He would spend significant amounts of time in the school and public libraries. His continued passion for learning is evident in this book. He can write eloquently about his condition largely because he has conducted extensive background research.

He describes how his parents had to support a large family on a low salary. They believed in Daniel and supported him through the many difficulties he faced. Tammet gives this advice to parents of children suffering from epilepsy or autism:

Give your children the self-belief to hold on to their dreams, because they are the things that shape each person's future.

Amen to that - the above advice applies to all parents (and teachers).

Tammet suffered from epileptic fits as a child and he tells the story of the day he almost died during a dramatic rush to hospital.

Language Abilities

Apart from having extraordinary mathematical abilities, Tammet can learn languages extremely quickly (he once learned Icelandic in a week). His website, Optimnem sells foreign language courses.

Born on a Blue Day gives some sound advice on how to learn languages (no doubt as a teaser for his language courses).


Most of the book kept me enthralled. It was fabulous to dig into such an interesting mind.

Unfortunately, the narrative tended to get off track somewhere around the 3rd quarter of the book, but it was saved by a strong conclusion.

Overall, I strongly recommend this book for anyone who has an interest in the workings of the human mind. It gives great insights into learning, autism, savant syndrome and the traumas of someone who craves orderliness.

See the 4 Comments below.

4 Comments on “Born on a Blue Day - summary review”

  1. alQpr » Blog Archive » Born on a Blue Day says:

    [...] I read ‘Born on a Blue day’ just one day before zac at squareCircleZ posted his summary review (having been led to the order the book after watching a video posted - also at SqCZ I think - a [...]

  2. Li-sa says:

    Does the book discuss the workings of the human mind when a person is experiencing emotions, such as elation, depression. anger or frustration?

  3. Murray says:

    Hi Li-sa. This is Tammets' autobiography, so it deals with his inner thoughts and emotions as he tries to come to terms with his autism and amazing mental abilities. It gives us an insight into ourselves, only in so far as all of us lie somewhere on the "autism spectrum".

    in fact, I wondered when reading the book how many mathematicians were actually somewhat autistic, since you have to be a bit obsessive and inward looking to be really successful in math. (Hope that doesn't offend anyone)

  4. The Gooser says:

    Hey great review! I had been looking to read the book and after reading your summary decided to give it a shot. I ended up loving the book and just wanted to let you know you gave a great summary without giving away the great ending πŸ™‚ Thanks again!

Leave a comment

Comment Preview

HTML: You can use simple tags like <b>, <a href="...">, etc.

To enter math, you can can either:

  1. Use simple calculator-like input in the following format (surround your math in backticks, or qq on tablet or phone):
    `a^2 = sqrt(b^2 + c^2)`
    (See more on ASCIIMath syntax); or
  2. Use simple LaTeX in the following format. Surround your math with \( and \).
    \( \int g dx = \sqrt{\frac{a}{b}} \)
    (This is standard simple LaTeX.)

NOTE: You can mix both types of math entry in your comment.


Tips, tricks, lessons, and tutoring to help reduce test anxiety and move to the top of the class.