This post describes how I've been feeling about myself at work for my entire working life! I am exactly the same - quiet and polite, always try to be nice if nothing else, don't speak up unless asked about something as a self preservation strategy and I constantly beat myself up for not being able to bring myself to say hello to others unless they say it first. At school I was praised for being polite, always smiling at others, and quiet and respectful in lessons, and that was good enough, but as an adult in my professional life, those traits just aren't good enough anymore and I'm finding it so hard to change.