define 'performance'

Recently we were asked to consider what we thought of as a performance. I think there are many different answers to this because, to some, life is performance. I know few people who consistently stand when in a room so that people will always have their eye on him/her. People such as these have a constant awareness that whatever they do will be seen by others and thus the world is their stage. This is not to say that they do not want to be watched, often i find these are the kind of people who thrive on attention and having all eyes on them. Then we were asked if something could be considered a 'performance' if the 'actor', as it were, did not know that people were watching them. I think that you cannot define someone as 'performing' unless they are aware that they are performing, otherwise you are simply reacting to what is going on around you. I believe that for a performance to occur, someone has to know what and why it is happening. For example a planned fight in a coffee shop can still be considered a performance even though the audience were unaware that they were watching it. Just as an altercation between two people could be considered a performance even if one person is unaware that the other has fabricated the whole argument. This is a seemingly straightforward question, the connotations of which are trickier to understand than first thought