We love a rags-to-riches story, and we love to see someone triumph through sheer determination. But the story is rarely that simple. My story isn't, anyway.

It is extraordinary to think of how lucky I have been'As the middle of five kids growing up in dire poverty, the odds were low on Katriona O'Sullivan making anything of her life. She became a mother at 15 and ended up homeless. Five rackety years followed - barely coping, drinking to escape - until Katriona, now living in her father's native Dublin, hit rock bottom.

Poor is the extraordinary story - moving, funny, brave, and sometimes startling - of how Katriona turned her life around. During her schooldays there had been teachers who looked out for her - beacons of stability in a chaotic childhood. They planted seeds of self-belief.

In Dublin when she sought help, she found mentors whose encouragement revived that self-belief. She got her act together, got a flat and a job as a cleaner, and got into Trinity College. Today Dr Katriona O'Sullivan is an award-winning lecturer whose work explores barriers to education.

Despite her professional success, and happiness in her marriage and as a loving mother, Katriona lives with the indelible legacy of her early years. Her book is a stirring argument for the importance of looking out for our kids, of giving them hope, practical support and meaningful opportunities. 'Deeply moving and thought-provoking' Louise O'Neill'Fearless, funny and searingly honest' Adil Ray OBE'A book that can change society' Lynn Ruane'Poor shows the strength of Katriona O'Sullivan's unbreakable spirit - she is a beacon of light' Patricia Scanlan