Other forms: caprices
On a whim, he sold everything and left the city for the beautiful wilderness of Alaska, but his act of caprice felt a lot less whimsical when he realized how freezing cold Alaska is.
The word caprice has its roots in the French for "whim," which comes from the Italian word capriccio for "fright" or "sudden start." A caprice can be just a fun impulsive act, but it also can be something done on a quick whim, without thinking it through or preparing for the change in direction. Having a sudden liking, or caprice, for someone or something can be short-lived too.