Books The Defining Decade: Why Your Twenties Matter--And How to Make the Most of Them Now  by Meg Jay (Author)

"The Defining Decade: Why Your Twenties Matter—And How to Make the Most of Them Now" by Meg Jay is a psychology and self-help book emphasizing the critical importance of the twenties as a foundational decade for the rest of life. Based on Jay's experience as a clinical psychologist, the book argues that choices made in this period shape career paths, relationships, and identity more than any other time.

Key concepts include "Identity Capital," the collection of skills, experiences, relationships, and personal assets built in the twenties that serve as a form of currency for future opportunities. The book advises choosing jobs based on potential for growth and learning rather than immediate pay, building broad social networks beyond close friends ("weak ties"), and engaging in deep self-reflection to recognize buried desires or fears ("The Unthought Known"). It encourages focusing on authentic personal and professional goals rather than external validation.