Dorveille

A dreamlike semi-conscious state, such as while falling asleep or waking up, between periods of sleep, or from exhaustion; generally with reference to an altered mental state where there is no distinction between the fantastic and the familiar. Most often used in reference to medieval poetry and literature.

Sonder

The realization that each random passerby is living a life as vivid and complex as your own.

Hypnagogia

That semi-lucid state between wakefulness and sleep where thoughts untether from reality and begin to get dreamy.

Frisson

A pleasant tingling feeling, associated with the flexing of hair follicles resulting in goose bumps, accompanied by a cold sensation, and sometimes producing a shudder or shiver.