How much of your life do you actually remember? Unless you happen to be a hyperthymesiac, probably not very much. Of course the whole question is extremely vague in the first place. Memory is normally contextual, and happens by association, so there are a great many things which you will remember in the appropriate context, but not otherwise. But my question is what you can remember without any particular context to guide you. Suppose you take pen and paper into an empty room and try to write down distinct events that you remember. Try writing one event that happened on each day of the past year. You will probably fail, although the total number of reasonably distinct events that you can remember will be much higher than 365, since you will remember many events for some of those days. But there will be other days where you can’t assign any particular event, even if you know generally what must have been happening.

Go back more than a year, and things will get more difficult. Within the next 20 seconds, think of something that happened in September 2005. If you can do that, what about September 15 of that year, or at least something close to that date? If you can do that, what did you have for lunch that day?

This will quickly become very difficult. I suspect that if you leave out the first five years of your life, which you probably mostly don’t remember on account of childhood amnesia, and the last year, of which you will remember more due to the recency effect, and take the above empty room test, you will not be able to write down a number of events equal to the number of days in the period, given reasonably distinct events, even allowing for writing down multiple events for a single day, and allowing for the fact that you can’t expect to remember on which particular day something took place. Of course this is merely my suspicion, and it could easily turn out to be mistaken.

In any case, whether my suspicion is right or not, much more than a single event happens in a day, and it is clear from questions like the one about the lunch you had on September 15, 2005, that you actually remember a fairly small proportion of your life, at least under ordinary circumstances, even if there are contexts in which you can remember more of it.

Thus your life as you remember it is much like someone’s biography, perhaps several hundred pages in length, but containing much less material than the person’s life contained in reality.