Fashion is a fickle thing.

The weather is fickle.

Fashion is a fickle mistress.

He is fickle.

A woman is ever fickle and changeable.

I'll eat almost anything, but I'm very fickle when it comes to cheese.

On this he burst forth into a tremendous passion, took leave of the mother with maledictions, and as he left the apartment, turned back to say to his weak, if not fickle, mistresss: “For you, madam, you will be a world's wonder”; a phrase by which some remarkable degree of calamity is usually implied.

If I wasn't a human girl I think I'd like to be a bee and live among the flowers." "Yesterday you wanted to be a sea gull," sniffed Marilla. "I think you are very fickle minded."

Man is as fickle as autumn weather.

Cats are fickle creatures.