There is a teaching in the Tao Te Ching that says "the Sage appears stupid."
On the surface, a wise person appears simple, attracts little public attention, worries little about what others think of his/her presentation. But sound the depth of his/her stillness and you find that he has resonances and overtones that the average person does not.
Cheng Man-Ching, taichi master, described a teacher like a bell: hit it with a small pebble and you get a small sound; hit it with a log and you get a big sound. If you don't even hit the bell, you may not even know the profundity you miss: thus the sage who appears stupid.
How to discern those with true wisdom from those who simply affect lightness of being? Listen deeply for the other's listening. Feel for their stillness of mind. For it is listening and receptivity which sound a teacher's bell. Everyone is a teacher if we are willing to learn; it just happens some bells are more resonant and helpful to us than others!
We cultivate a resonant bell by investing time and energy in our own stillness of mind. In the silence between thoughts comes knowledge - knowledge is an awakening rather than a learning. In an awake state we see more clearly and have more insight, intuition and information. With these tools we see farther into the horizon, make better choices, define clearer boundaries, organize thoughts better, become more stable in the face of strong emotion or stress. We have our own answers within: we simply need to know how to seek them and live them.