The document discusses how hearing about various concepts like trees, the sea, the sun, etc. leads to envisioning them in a certain way, but it is only by direct experience that one comes to realize deeper aspects of each concept. For each concept, the author contrasts what was initially imagined based on hearing about it, with what was realized through direct experience such as swinging from tree branches, swimming in the sea, standing under the sun, and so on. The document suggests that doing or experiencing something firsthand provides a more complete understanding than can be gained through mere description or imagination alone.