The less you associate with some people, the more your life will improve. Any time you tolerate mediocrity in others, it increases your mediocrity. An important attribute in successful people is their impatience with negative thinking and negative acting people. As you grow, your associates will change. Some of your friends will not want you to go on. They will want you to stay where they are. Friends that don’t help you climb will want you to crawl. Your friends will stretch your vision or choke your dream. Those that don’t increase you will eventually decrease you.
— Colin Powell