With today's medicine and therapeutic procedures, we can alter our anatomies to suit the gender we believe is our own. But many individuals never managed to reconcile themselves with their identities, torn by ambivalence between biology and social roles. Forming an identity is like putting together a puzzle, each of whose pieces are taken from your familial and social surroundings. Psychiatrist and psychoanalyst Serge Hefez has written an ambitious and accessible book urging us to do away with the preconception that knowing who you are means fitting into existing categories.