Dr. Jackson and Teal'c in “Unfinished Business”

This is interesting. It's a reference to Merlin's prophetic abilities. There's a similar myth on Earth. That Merlin could see the future because he actually aged backwards in time. It's not meant to be taken literally, but we have seen a lot of legends and folklore have a strong basis in fact -- Avalon, Atlantis.

The Easter bunny.

I guess there's a few exceptions.