How many times have I heard that quote ringing in my head, particularly now as I look over the mountains of paperwork that I am trying to scan and/or organize.
So much of my early research was not documented, or when it was documented, the documentation was incomplete. I would highly recommend Evidence! by Elizabeth Shown Mills, as a guidebook for genealogical citations. As I slowly and painfully go through the process of adding source citations to my 'facts' in my family tree database, I want to kick myself for not doing this as I went along.
When I started out, I assumed that I would always remember where I heard that great-grandpa Wright was born here, or that uncle so-and-so went west and was never heard from again. Now, I struggle with the embarrassment that so much of my database is undocumented. Undocumented, my friends, is practically worthless.
My recommendation to those who are starting out is to document, document, document! When you send a chart to a far-distant cousin, and they want to know where you obtained the birth date for great-aunt Martha, you don't want to have to say "I dunno?!"
Jesus Christ had Matthew, Mark & John to give eyewitness testimony, and Luke, the historian, was able to interview eyewitnesses to the resurrection. Unfortunately, in my database, there is more hearsay than documented facts at the moment.