When I say look, I'm not particularly concerned about other cyclists..... rather cars.... If you are riding on the road and don't look before you move you risk being run over. It doesn't matter that cars are *supposed* to give you 3 feet, they don't always and while they are generally noisy you can't always rely on your ears alone. If you don't feel comfortable turning you head to look or can't do it without moving your bike around practice (or think about a mirror). It may save your life someday