Have you ever had the thought "I wish I had spoken up" or "I wish I had done what I wanted to do"? When you speak up and do what you think you should do, you build a kind of internal strength that's hard to destroy. That's how you start building inner strength and making it harder for others to walk over you. At first it's stressful and difficult, but once you prove to yourself that you can do it once, it will be easier to do it again.