Do we have the capacity to recall everything we've ever experienced, even if under

[raccoon]

hypnosis, truth serum, or something?

Or are some memories just gone?

[CJCRANE]

1. "Hyperthymesia

or hyperthymesitic syndrome is superior autobiographical memory, the type of memory that forms people's life stories. The term thymesia is derived from the Greek word thymesis, meaning "memory".[1]

The capabilities of the affected individuals are not limited to recalling specific events from their personal experience. Hyperthymesia has both enhanced autobiographical and episodic memory[1] There are two important characteristics of hyperthymesia:

1.Persons with the syndrome spend much of their time thinking about their pasts.
2.Persons with the syndrome have an unusual, amazing capacity to remember as well as recall any specific personal events or trivial details, including a date, the weather, what people wore on that day, from their past."

I heard a radio program about. They asked one guy some questions about random dates in the past and he could remember news stories, the weather etc. He said it was natural and spontaneous, he didn't use any memory tricks and he didn't spend much time thinking about it. IIRC it affects about one in a billion (or some ridiculously small number of people).

http://en.wikipedia.org/wiki/Exceptional_memory#Hyperthymesia

[cthulu2016]

2. No. Not even close.

Some people have fantastic recall for numbers and music and chess games, but in terms of recalling experience, no. Not even close.

And it is easy to see why we cannot have the equivalent of a rolling video of our lives being stored. We use a big chink of the brain in processing our moment-to-moment sensory input. To store that processing in full would require more storage space than even our impressively complex brains could manage, as basic arithmetic.

Me translate experience into compact symbols—after the fact processed representations of experience—and then expand those symbols on recollection. Obviously major data loss along the way.