John, I can understand your confusion, but the second had information and the [[ ]] are two different things.
"It's a good idea to include who said certain information, and if you remember, when they said it."
In the example given, it could just as easily say -- Edward Whitten related the story about his childhood to Chris Whitten on Christmas Day 1979.
It then says: "You may also want to include a link to the person's WikiTree profile page."
The double bracket [[ | ]] creates the link to the profile of whoever said the information. Use-- double bracket wikitree-ID bar name double unbracket. Examples [[Whitten-1|Chris Whitten]] or [[B-404|Anne B]] or [[Nash-3461|John Nash]]
Help page on creating links.