Do we remember only 3% of our lives? [origin of "factoid"]

[engineer_comp_geek]

Moderator Note

I have removed most of the posts in this thread that discuss memory and the factoid itself. Those posts may now be found in the MPSIMS thread here:

Do we remember only 3% of our lives? [discussion of "factoid"]

This thread has been broken out of the FQ thread of a similar title. The FQ thread discusses the origin of the “factoid” that we only remember 3% of our lives. This thread is for discussion of the factoid itself. The original FQ thread may be found here:

Please use the MPSIMS thread for discussion of memory issues and the validity of the factoid itself, and keep this discussion if FQ focused on the origin of the factoid.