Two of the nation’s leading feminists and hosts of the hit podcast Call Your Girlfriend make the bold and compelling argument that a close friendship is the most influential and important relationship a human life can contain—helping you improve as a person and in your relationships with others.

It’s a given that a deep, fulfilling friendship is a key to happiness—everyone from Greek philosophers to Instagram influencers will tell you that! But for all the rosy sentiments surrounding friendship, we don’t talk much about what it really takes to stay close friends for the long haul. Now two friends, the popular podcast cohosts Aminatou Sow and Ann Friedman, elaborate on their equally messy and life-affirming Big Friendship in this honest and hilarious book that chronicles their first ten years in one another’s lives.

Aminatou and Ann define Big Friendship as a strong, significant bond that transcends life phases, geographical locations, and emotional shifts. And they should know: the two have had moments of charmed bliss and deep frustration, of profound connection and gut-wrenching alienation. They’ve been, at various points, inseparable companions, long-distance support providers, work wives, estranged relatives, next-of-kin, and everything in between. They have weathered life-threatening health scares, getting fired from their dream jobs, and one unfortunate Thanksgiving dinner eaten in a car in a parking lot in Rancho Cucamonga. And they both agree: the most important part of a Big Friendship is making the reciprocal, firm decision to invest in one another the way you would invest in yourself.

An inspiring and entertaining testament to the power of society’s most underappreciated relationship, Big Friendship will not only validate the energy you’ve invested in your friendships, but also offer a guide to how these bonds are formed, challenged, and preserved.