Guru conveys by their very presence the concentrated essence of being themselves, as one with all, as one through all. So being, their role becomes role-play. A play of roles that is interactive, interchangeable and transferable.
There were no banks. The wealth of one person was banked as memory. The wealth of one family was banked as progeny. The wealth of one tribe was banked in stories. The wealth of one story was banked in continuity.