The more names you add to your address book: both personal and professional: the happier you are. After all, meeting new people is one of your favorite pastimes. Introduce yourself to a neighbor you've never talked to before, chat with your seat mate on the bus or go out of your way to welcome a new coworker. Of course, you probably aren't going to connect with every person you meet, but it never hurts to make an effort. If you get one new contact or potential friend out of it, you're better off than if you hadn't tried at all.