Max at rest.

Reverie
noun
a state of being pleasantly lost in one's thoughts; a daydream : a knock on the door broke her reverie | I slipped into reverie

-Music an instrumental piece suggesting a dreamy or musing state.
- archaic a fanciful or impractical idea or theory.

ORIGIN early 17th cent.: from obsolete French resverie, from Old French reverie -rejoicing, revelry, from rever- be delirious,- of unknown ultimate origin.

Cats on Holiday