The youngest and only boy of four children, Arndt attended Hotchkiss School, a private school in his native Connecticut, and won a fellowship to a 13th year at Harrow College in Northwest London. He earned his undergraduate degree in history, with honors, at Yale University in 1990, where he was captain of the undefeated golf team, named All-New England golf champion for two years, and All-Ivy champion for three years. He was a member of the Sigma Nu Fraternity. He played professional golf for a time, and worked for five years as an investment banker for Morgan Stanley in the US, Europe and Asia as well as in a variety of capacities in the entertainment industry in Los Angeles. He then entered Harvard University for an MBA in 1996. He was President of the Harvard Graduate School Leadership