This message is about setting boundaries, and understanding that you have the control and autonomy to decide what want to do and not do. Oprah spoke about this on her show, specifically around the topic of sexual abuse, and empowers people to choose what is best for them.
The best thing to do to know your boundaries is to state where your boundaries are before the moment arises. Whether it is the number of drinks on a night out, or times you will try to reach out to someone, it is best to determine that amount in an unemotional state. And something that you could try to stay accountable to that amount is writing it down somewhere. There is strong commitment to your own handwriting.