This document discusses the brain and memory retention. It provides examples of how much information is retained from viewing or listening to information over different time periods. The key points are: - People retain about 27% of information presented in the first 10 minutes (prime time 1), but only 10% of information presented between 10-20 minutes (prime time 2). Retention drops to 8% for information presented between 20-80 minutes (down time). - Retention is highest, around 90%, for information presented in prime time 1, and lowest, around 62% for information presented in down time. - Most information is forgotten within the first 24 hours, according to the forgetting curve presented. Retention drops significantly