Thousands of donor-conceived people have a deep longing to know who they belong to, where they come from, and who they look like. What is it like to grow up not knowing who your father is or if you have any siblings? What is it like to find out that the man you thought was your dad is not your biological father, that your true biological father donated his sperm and is known only by a number? How does it impact your self-perception, the choices you make, and your view of life and the world? Donor-conceived people are demanding answers to these basic questions about their origins, their lives, and their identities.