I am reading clinical psychologist Meg Jay’s book titled The Defining Decade: Why Your Twenties Matter — And How to Make the Most of Them Now. Her take? That eighty percent of life’s defining moments take place by thirty-five. Therefore, she is giving advice to those in their twenties to make the most of this “defining decade.” From the book description:

Our “thirty-is-the-new-twenty” culture tells us the twentysomething years don’t matter. Some say they are a second adolescence. Others call them an emerging adulthood. Dr. Meg Jay, a clinical psychologist, argues that twentysomethings have been caught in a swirl of hype and misinformation, much of which has trivialized what is actually the most defining decade of adulthood.

Drawing from a decade of work with hundreds of twentysomething clients and students, THE DEFINING DECADE weaves the latest science of the twentysomething years with behind-closed-doors stories from twentysomethings themselves. The result is a provocative read that provides the tools necessary to make the most of your twenties, and shows us how work, relationships, personality, social networks, identity, and even the brain can change more during this decade than at any other time in adulthood-if we use the time wisely.

In the preface of the book, Jay states: “It might even seem like adulthood is one long stretch of autobiographically consequential experiences — that the older we get, the more we direct our own lives. This is not true…. In our thirties, consequential experiences start to slow down. School is over or nearly so. We will have invested time in careers or made the choice not to. We, or our friends, may be in relationships and starting families. We may own homes or have other responsibilities that make it difficult to change directions….as thirtysomethings and beyond we largely either continue with, or correct for, the moves we made during our twentysomething years.”

I do think Dr. Jay is on to something. Many people think the twenties don’t matter, that there is plenty of time to lay a foundation for one’s life later on, and that after thirty, everything will come together. Sometimes it does and sometimes it doesn’t. The book seems good at helping those in their twenties make decisions about what they want to do and where they want to be. Sometimes hoping for the best doesn’t work, but goal-oriented behavior does.

However, while I get her point — don’t waste your twenties — I don’t think that life’s defining moments mostly take place before thirty-five. There are many things that happen through our lifespan, each one special and consequential to us as individuals, that take place at different times (some sooner, some later). Many people fear reaching thirty as they think life is over and our society often concurs. However, many great things happen after that age, some more consequential than when one was in their twenties; to think that any decade is one’s best or only chance is to put a cap on human potential, a waste at any age.

More from Dr. Helen: 

“Young women who want to be rich and powerful should major in economics or engineering and be prepared to work 60 hour weeks.”