Most people would admit that people, including themselves, can be mistaken about a memory.
However, our egos get bruised when we are confronted with our own mistakes of memory, and we often secretly believe that our memory is better than that of others.
In day to day life, being mistaken is usually no big deal, but when it comes to the criminal justice system or some childhood trauma, it can become a vitally important subject. Just how accurate is eyewitness testimony or your memory of some perceived traumatic event especially in childhood?

One of the central functions of memory, is not to make perfect recordings of events. Instead, memory is similar to imagination, and it tends to create narratives in which we are the central actors, and in which our current beliefs, emotions, and worldviews are continually confirmed. Memory is one of the ways that our brains maintain the illusion of an unbroken narrative of the self.

Once you grasp the purpose of memory, it should make you quite humble — and very reliant on fact-checking with multiple sources before concluding your memory of something was correct !