woolgathering

The act of gathering wool: usually applied figuratively to the indulgence of idle fancies or to any foolish or fruitless pursuit.

Indulging in a vagrant or idle exercise of the imagination; roaming upon a fruitless quest; idly fanciful.

Indulgence in idle imagination; a foolish or useless pursuit or design.

Gathering fragments of wool torn from sheep by bushes, etc.

Indulging in idle fancies or daydreams.

an idle indulgence in fantasy

dreamy in mood or nature