The biggest mistake I made while at United Rentals was to trust that my boss had my best interest at heart and would live up to the promises he would make. Won't make that mistake again. Almost 11 years wasted on an unappreciative Irish douchebag. He only cared about one person - himself. It's a shame that he is on the fast-track to become the next CEO (after Flannery retires) because he is the absolutely worst boss I've ever had. He shouldn't be allowed to have direct reports - he is really that bad.