Character is the public perception of who we are. We are perceived a certain way by the people we meet through first impressions and interactions. Once you build up a good character for yourself it can be fragile. For example, if you make a mistake, it might take days, months, or years to make up for that mistake. Your reputation is built up later by layer over a long period of time but can be torn down within seconds. The same goes for the building of your character. This shows how important thinking about your actions pays off.
