Ancestors Show Up in Your Time of Need

In the original Star Wars, Obi-Wan Kenobi returns from the dead to remind Luke to trust the Force. In The Lion King, Mufasa appears in the clouds to advise Simba. Mulan had a whole group of deceased ancestors watching out for her. And if I recall correctly, something similar happened in Field of Dreams. Movies often have inspiring scenes of the lessons we learned from our forefathers coming back to save us when we really need it. But how far back can you go before the wisdom of our beloved relatives is totally useless? Don't mind the length of the video, the skit is only 3:50.