What is existence 

Normally, we experience the "existence" of a subject (conceived as oneself) and an object (conceived as individuals and things of the world). We (the self) also tend to become emotionally involved with (things of the world). We get involved by forming relationships between the subject (self) and objects (of the world). Because we get involved with the existence of oneself, others, and the relationship, we tend to forget that this existence is only an "experience." We tend to take the "existence" to be very real. This is why the separation from our loved ones makes us so unhappy. This is why the death of a relative or friend results in immense grief and lamentation. When, however, we begin to become aware of the "experience," which is the basis of existence, through vipassana meditation, the "existence" is found to be less real. Ultimately we realize that this "existence" is only an illusion (a perceptual fallacy) or more correctly a delusion (a conceptual fallacy). This is the "awakening" (sambodhi) from the "dream of existence." This is also called the "cessation of existence," which is Nirvana (bhava nirodho nibbanam).