in a fog
Also, in a haze. Preoccupied, not paying attention; also, at a loss, confused. For example, After the accident he went about in a fog, even though he had not been injured, or Millie always seems to be in a haze; she never knows what's going on. These expressions allude to fog or haze obscuring one's view; the fog usage dates from about 1600, haze from about 1800.
Words nearby in a fog
in a cold sweat,
in a dither,
in a fix,
in a flash,
in a flutter,
in a fog,
in a good light,
in a hole,
in a huff,
in a jam,
in a lather