quixotic

Resembling or characteristic of the Spanish chivalric hero Don Quixote; possessed with or resulting from the desire to do noble and romantic deeds, without thought of realism and practicality; exceedingly idealistic.

Not sensible about practical matters; idealistic and unrealistic

“as quixotic as a restoration of medieval knighthood”

“a romantic disregard for money”

“a wild-eyed dream of a world state”

rareA quixotic person or sentiment.