The Book of Memory
I believe Judy Ann Nock said it best:
The religious practices upon which Wicca is partially based were primarily an oral tradition passed down to neophytes by more experienced practitioners. It’s said that small groups of practitioners met in secret and would posses little knowledge of the whereabouts of other groups. This was done for protection, so that if one group was discovered there would be no way for the members to reveal or disclose the whereabouts of other practitioners. Unfortunately, this fragmented approach has left us severely wanting in the area of verifiable information. It is very difficult to piece together the rites and rituals of an oral tradition when the practitioners are scattered and disjointed and few records exist.
When so much information is missing, it becomes our responsibility to rewrite the rituals and legends as they relate to our modern experience. We may never go back, only forward.