I’ve been getting into reading more biographies, and for the most part, it’s been great, but there’s always a lingering thought in my head asking: how much of this is real? I remember large phases of my life, and I get that a biographer would interview people around them/take countless hours trying to remember the past, but how can you remember so many things in such great detail?
Check the acknowledgments in any decently researched biography and you will see a litany of thanks to various librarians and archivists for their assistance in helping the author find resources about the subject of the biography.
Libraries and archives are vital for any serious biographical research (or serious research, period.)