Unfortunately for individuals and businesses, one maxim is universal – one false move and years of investment in a brand or business can be lost (or tarnished for a long period of time). This is because brands reside in the "land of perception" where the truth comes second, and minds can be made up on information of varying levels of veracity. Perception is what you must manage, and this requires investment. And perception can be influenced in more than a single facet.
For example, I might think that Tesla is a really good brand but the fact that they are effectively a luxury good positions them in my mind in a particular way. That undergoes further change when I hear that you cannot really drive one to Auckland without connecting to a charging station along the way. My perception of the brand, and product, is influenced by those things (which may or may not be truisms), which will dictate how I will interact with the brand in the future.
So, it will come as no surprise that the most effective marketing is "word of mouth" and the same is true of maintaining and building your brand. People will form an opinion of you and your business and express this in the market – in a lot of cases these opinions may not even be those of your clients/customers. Indeed, your competitors may be in the market trying to influence perceptions and, by implication, your brand.
Much of what you do to maintain that outward presence starts on the inside. Your brand is often developed and positioned by the "why" of your business and the things that most people do not see. So, it is important to have a strategy, a purpose, and have your house in order to have in place controls to make sure that things do not go awry – particularly when it comes to delivering service. A streaming service crashing at 8.20pm on a Monday (and sending a message that they are "doing maintenance") is a good example of a disconnect in this area.
And it can be the most innocuous of incidents that can deflate a strong brand. So, if you have (or want) a good reputation for the things you want to be positively renowned for, nurture your brand and invest to build and protect it.