In Japanese there's a saying "another loach" in the short form, "look for another loach under the same willow tree" in the long form.
This saying is for ridiculing a person who blindly repeats what s/he once successfully did, or who imitates what somebody else successfully did, in the hope that s/he can succeed again not knowing s/he would surely fail the second time.
It comes from a famous folklore about a man who once captured a loach (like a catfish) in a stream under a willow tree, who tried unsuccessfully to catch another loach exactly at the same spot.
I am wondering if there is a saying in English similar to this?