What were you doing on February 14th of 2007? On which tasks were you working on that very day you met your girl friend? When was the last appointments with your dentist? Who called you on telephone during that meeting with your customer last month?
Most people can not answer such questions. With Memacs you can!
Memacs extracts metadata (subjects, timestamps, contact information, …) from many different existing data sources (file names, emails, tweets, bookmarks, …) on your computer and generates files which are readable by GNU Emacs with Org-mode.
This might be useful for some people. But for most of us we don’t need to know this stuff and it can pay to forget it. The idea is that you’re offloading memory load into the computer but actually you’re increasing your load because you’ve got to keep some kind of handle on what information you have. And it’s very easy to offload too much that you should have remembered.