The Defining Decade is the book every twentysomething needs to read. Not only will it light a fire under your rear to set your adulthood up for success, but it will teach you how to do it. Based on decades of research as a psychologist specializing in young adult development, Meg Jay confronts the modern issues millennials are facing in our convoluted social, economic, and career landscapes.

The “thirty-is-the-new-twenty” culture tricks us into believing our second decade doesn’t matter. Misplacing the value of this time as a period to savor a “second adolescence” ultimately cripples young adults when they’re faced with important, life decisions. By weaving the latest research with case studies from her clients, Jay provides essential tools to make the most out of your twenties. She walks us through how work, personality, relationships, identity, social networks, and your mind can change more during this time– if we choose to take action on the years we cannot afford to miss.

Separated into three parts: “Work,” “Love,” and “The Brain and the Body,” Jay explores physiological reasons why millennials should feel motivated to seize the day. As explained in an NPR interview:

“We know that 80 percent of life’s most defining moments happen by age 35. We know that 70 percent of lifetime wage growth happens in the first 10 years of a career. We know that more than half of Americans are married or living with or dating their future partner by 30. Our personalities change more in our 20s than any other time. Our fertility peaks. Our brain caps off its last growth spurts … The things that we do and the things that we don’t do are going to have an enormous effect across years and even generations.”

FullSizeRenderThinking about the future can be intimidating, even paralyzing, for twentysomethings. We rightfully savor the present moment but procrastinate on planning ahead. Before you know it, it’s too late– as it’s actually harder to establish your adulthood lifestyle by the time you’re 30. Make your life easier by preparing yourself now for the life you want to live later.

There is no time to waste. Jay further motivates her readers: “There are no guarantees. So claim your adulthood. Be intentional. Get to work. Pick your family. Do the math. Make your own certainty. Don’t be defined by what you didn’t know or didn’t do.”

As a 22-year-old self-employed woman, I truly cannot emphasize more how this book has served as a critical piece in organizing the foundations of my adulthood. I could not recommend this book more.