Simply put, a conflation is an amalgamation of two different expressions. In most cases, the combination results in a new expression that makes little sense literally, but clearly expresses an idea because it references well-known idioms. All conflations fit into one of two major categories: Congruent Conflations & Incongruent Conflations.
Incongruent Conflations occur when the root expressions do not mean the same thing, but share a
common word or theme. For example, “a bull in a candy shop” can be formed from
the root expressions “a kid in a candy shop” & “a bull in a china shop.”
The former root expression paints a picture of someone who is extraordinarily happy and excited, whereas
the latter root brings to mind the image of a person who is extremely clumsy. The conflation potentially
expresses both of these ideas at the same time without making the speaker’s intention entirely