I have an interesting story on how I started.  Many years ago (ack 10 or more now) I was the admin to the director of operations at a biotech company.  Our staff meetings was a group of managers that reported to him and myself.  There was one female manager who just impressed me, she just had the total package of smarts, knowing  how to work in a male environment, always looked great (was not thin but always looked so polished).  I noitced her notebook and how she kept all her notes from phone calls, small details, to things people would talk to her about.  I just decded she was a great person to watch and learn from.  So I started one and never stopped.  

I still have my notebooks from years back.  Once in awhile I go back, see some of the meeting I planned an laugh at some of the problems and just things that happend that I caught in the notebooks.