Responsible is more easily pointed at by saying what constitutes not being responsible. Acts of irresponsibility include blaming another, blaming yourself, feeling like a victim, being defensive, and/or not choosing courage, when choosing courage would best serve you. It also would include creating curiosity and compassion for yourself if you notice you didn't choose courage. It includes standing in the place where you hold yourself fully accountable for creating what you intend to have in your life.
This distinction stands in sharp contrast to other definitions of responsibility, like "being dutiful, loyal, or doing what society expects of you."
Werner Erhard provides a good idea of this distinction:
“Responsibility begins with the willingness to take the stand that one is cause in the matter of one’s life. It is a declaration not an assertion, that is, it is a context from which one chooses to live. Responsibility is not burden, fault, praise, blame, credit, shame or guilt. In responsibility, there is no evaluation of good or bad, right or wrong. There is simply what’s so, and the stand you choose to take on what’s so. Being responsible starts with the willingness to deal with a situation from the view of life that you are the generator of what you do, what you have and what you are. That is not the truth. It is a place to stand. No one can make you responsible, nor can you impose responsibility on another. It is a grace you give yourself—an empowering context that leaves you with a say in the matter of life.”
-Werner Erhard (American author and lecturer known for founding "est," which operated from 1971 to 1984. He co-created the Landmark Forum in 1894. 1935-)