The word character is a favourite of mine especially when used to describe someone's behaviour. Why? It's because a character is someone playing a part, a role, in some kind of drama. Our personal character that we develop is based on choices we make throughout life that become consistent to the point that you can be depended on to exhibit that behaviour. But it is all an act! It's just some game you are playing and you can change it at any time and play another role. But then the people who 'know' you will think you have gone crazy and are acting out of character!