"Memento" teen Ricky Dean lives in a peculiar world. The Daily Mail reports that the 19-year-old from Somerset, England, must constantly set alarms and leave notes all over his family's house in order to remember the most simple daily task. Just like Guy Pierce's character in the Christopher Nolan film, Memento, he must surround himself with lists telling him exactly what to do next.

Dean, who suffers from an extremely rare form of short-term memory loss, has no concept of time.

"It can be very difficult at times, but my family and friends are so supportive," he said in a recent interview. "My condition can be so frustrating for people, especially if they don't understand that I just don't remember anything to do with time. If I didn't have my lists, telling me to brush my teeth or have lunch, I would be lost."

"The worst thing is missing appointments with friends and forgetting good things. I can't look forward to anything," he continued.

Starved of oxygen as a newborn, Dean was initially thought by physicians to have autism. He lived with the misdiagnosis until a brain scan finally revealed the extent of his memory loss. The condition has no formal name, much less a treatment.

'We knew something was wrong when he was seven. To get a diagnosis was a relief because we had been saying all this time that he wasn't doing all these things because he wanted to," Nicki, Dean's mother, told reporters.

Until about three years ago, Dean rarely left his home, fearing he would get lost or forget where he was going. Today, a slew of alarms and organization apps on his iPhone allow him to navigate outside without losing sight of his destination or his parents' house.

"We try to promote independence but tasks such as cooking or running a bath present too much risk, because he wouldn't know whether the oven or bath had been on for five hours or five minutes," his mother said. "He has come so far and is an inspiration to others."

His father, Gary, notes that as far as science is concerned, his son's mixture of autism and memory issues is one in a billion. It takes almost nothing to distract him from a task, and he frequently stops dead in his tracks, usually to offer others help.

Besides the many lists and blackboards around the house, Dean always carries certain emergency reminders, such as his "If I Get Lost" card. If he ever loses his way, the bullet point list helps him remain calm and remember all relevant phone numbers and addresses.

"My mates are constantly having a joke about it, which is good, telling me I borrowed a tenner from them the week before. I can never remember if I have or not, so I make a list and if they're just winding me up I get my own back," Dean told reporters.

His vague conception of time notwithstanding, Dean has completed five general certificates of secondary education and is currently studying agriculture and horticulture.