“Human brains are terrible at keeping track of a series of small numbers, and equally bad at accurately measuring time.

“Searching comes in tiny chunks of time, most only a few minutes or less, spread out over the entire week.

“As an activity, it could not be better designed to fool our brains.”

http://www.meemim.com/2016/04/11/esn-and-intranet-usage-and-their-effects-on-information-accessibility/