Once' is a word that means 'at one time' or 'on a single occasion'. It is often used to refer to something that happened in the past, but could also be used to refer to something that may happen in the future. The phrase 'in another life' implies that something could have been different if the circumstances were different. It suggests that if things had been different, then the outcome would have been different. This phrase is often used to reflect on what could have been and to imagine a different reality.