The Defining Decade: Why Your Twenties Matter & How to Make the Most of Them Now #SarahsBookSoiree

This post is a summary of why you should read :

The Defining Decade: Why Your Twenties Matter and How to Make the Most of Them Now

I’ve recommended this book to everyone since reading it. I personally think this book spurred me on to create this blog, that’s how much its changed my life.

Clinical psychologist Dr Meg Jay writes about her experiences working with twentysomething year olds who are trying to navigate their way through life and sometimes avoid their responsibilities because they’re scared of what the future holds. Or these twentysomethings are idle in both their love and work life and need that kick in the right direction to stop them wasting one of the most important periods of their lives, their twenties: The period where people lay the foundations of their wealth and tend to be free from commitments like marriage and children. The book also warns of the dangers of being idle in your twenties and why you should not let time pass you by.

The book is split into three sections:

  1. Work
  2. Love
  3. The Brain and the body


Contains several stories and anecdotes relating to those who have stayed idle in their twenties and rather than taking charge of their lives, were waiting for someone to come along, and carry them on their journey, kinda like a bouy in the ocean, swaying from side to side wondering where the sea would take them.

If we only wanted to be happy, it would be easy; but we want to be happier than other people, and that is almost always difficult, since we think them happier than they are.

Charles de Montesquieu, Writer/Philosopher

Work also discusses the dangers of social media, how young people complained that their “life should look better on Facebook” and then got upset when they saw other people living “better” than them. Which is why we shouldn’t compare ourselves to others because it does nothing for our lives and leads to you feeling less empowered and more helpless.

Another issue discussed were how people avoided the uncertainty the comes after making decisions because they were afraid of the unknown.

It talks about unthought known which are things we know about ourselves but somehow forgot. These could be dreams that we have lost sight of or the truth we sense but don’t say out loud, people tend to be afraid to say these thoughts to others due to how they may react and hide them from themselves because they are afraid of the outcome.


Discusses the dangers of dating without purpose as it leads to people panicking then settling down when they suddenly hit 30 with people they don’t actually like and are not compatible with. The dangers of cohabiting are mentioned and how it elongates dead relationships because people don’t realize they’re no made for each other until a long time after and sometimes have to stay due to signing a long term tenancy agreement. It also talks about the big five personalities: openness, conscientiousness, extraverison, agreeables, neuroticism. These personalities give you an idea of how you react in different situations. It also states the obvious, good sex and your partner being attractive isn’t a good reason to stay with them.

“What counts in making a happy marriage is not so much how compatible you are but how you deal with incompatibility.”

Leo Tolstoy, Writer

The brain and the body:

Spoke about how the brain is still developing in your twenties and the sheer panic people face entering their first job after university, something I related too when doing my placement. Also says How employed 20 year olds are happier than their unemployed counterparts. How being in a relationship can make you feel more secure and responsible and although being single is glorified in the press it doesn’t particularly feel so good. My favourite part of this section was the talk about managing fertility. Fertility peaks in your late twenties but starts to decline at thirty and thirty-five because the woman’s ability to carry a baby to full term decreases, meaning miscarriages become more likely and eggs have trouble implanting due to hormones. Fertility in men also declines as older sperm is associated with neurocognitive problems in children such as autism, schizophrenia, dyslexia and lower intelligence overall. Which is why it is important for both sexes to think about their fertility.

“When we try to do something new we don’t know what we’re doing. that’s the biggest challenge”

Jeffrey Kalmikoff, Designer

To summarize:

The overall messages I got from reading this book are:

  1. It is better to start divulging into new experiences now than wait until your thirty to start doing new things because contrary to popular belief. Thirty is not the new twenty. There is a big difference between having a life at thirty and starting it at thirty.
  2. Life will not stop for you. Time will keep going, your friends will keep going, so you need to get going and start working towards your future.

Feel free to buy the book here:

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