Have confidence in what you do and respect yourself. Don’t let insecurity dictate your life. Some of us use these pitiful actions to avoid embarrassment, resentment, and the like. You don’t need to feel like you owe everyone an explanation, most of the time you are not even asked for it. It may be an automatic defense action, but it won’t be good for you. You will just end up looking like a wimp, and people will respect you less. Don’t harm yourself this way.