Autobiographical memory means more white matter
It’s “Total Recall” meets “The Good, The Bad and The Ugly” for at least 33 people in the world who can recall every detail of their lives (since about age 10) perfectly. Recently, researchers found that those with autobiographical memory have variation in 9 structures of their brains (compared to most people), including more robust white matter linking the front and middle parts of the brain.
http://www.medicalnewstoday.com/releases/248452.php