Henry Moliason suffered from severe epileptic fits when he was young, so in 1953, at age 27, he took a drastic measure. He authorized a surgical procedure to remove much of his hippocampus, where the source of the seizures lie. It worked—but it also robbed him of the ability to make memories. From 1953 to 2008, when he died, Moliason was unable to form any new memories. What's more, it turned out that not having a sense of the past impacted his sense of the future.