Dreams; the mystery of their essence

What is reality? How much can we rely on our senses? What if our awakened moments of reality are just a dream, and we sleep to enter reality? What if we have mis-identified reality and dreams? And maybe the doorway between the two gets opened on occasions other than our sleep. We dream of people. People dream of us. Two persons, miles apart, can dream the same dream and meet each other in their dreams, and upon waking can tell each other how they met in the dream - shared dreaming. Often, the reality of dreams scares us and therefore we choose not to explore into the secrets of their reality.