While it is common for memoirs to be written in first person, it is not a requirement. A memoir is a genre of writing that tells a true story about a specific time or event in the author's life. The focus of a memoir is typically on the author's personal experiences and emotions related to the event, rather than a comprehensive recounting of actual events. As such, it is not uncommon for the author to write in first person.
However, there are examples of memoirs that are not written in the first person. For example, some memoirs are written in third person, which can create a more objective perspective on the events described. In these instances, the author may use their own experiences as a starting point, but could choose to tell the story from a third-person point of view.
It's worth noting that the line between memoir and autobiography is often blurred. Autobiographies are typically written in first person and are more focused on chronologically recounting the events of the author's entire life. Memoirs, on the other hand, are more focused on a specific event or time period, and are often more personal and emotional than autobiographies.
Ultimately, it is up to the author to decide what perspective to take when writing a memoir. Whether it's written in first or third person, the goal of a memoir is to tell a compelling and truthful story that helps readers connect with the author's experiences.