Have you ever felt like you were too young or too inexperienced to make a real difference in the world? I just finished a book by a woman whose story is sure to change your mind.

Jacqueline Novogratz, author of The Blue Sweater: Bridging the Gap Between Rich and Poor in an Interconnected World, got her start in the changing-the-world business at the ripe old age of 25. It was in the mid-1980s, long before eradicating extreme global poverty hit the mainstream consciousness in this country, that she left a lucrative job in international banking at Chase and set out on her own for Kigali, Rwanda with a heart for helping the poorest of the poor to help themselves.  

More than two decades (and a book full of frightening and inspirational experiences) later, she is now the founder and CEO of Acumen Fund, a nonprofit venture capital firm that invests in entrepreneurs bringing affordable and sustainable healthcare, water, energy and housing to people earning less than $4 a day.