Once upon a time, the Ascended Masters--souls who had successfully learned all of the lessons that living on Gaia has to give, spiritually--walked the planet freely with everyone else.
They ran the mystery schools.
In other words. Yoda and the other Jedi Masters had their Padewan schools on the surface of Earth.
What happened?
If you are interested, here is the answer:
http://2012portal.blogspot.com/2013/04/mystery-scools-before-this-planet-was.html?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+blogspot%2FjUQcb+%28Portal+2012%29
Namaste,
Reiki Doc