I am expected to write a narrative which describes "an inadvertent comment that was so inane you felt embarrassed afterwards;and how you reacted when you realised what you had said."

Question

I am expected to write a narrative which describes  "an inadvertent comment that was so inane you felt embarrassed afterwards;and how you reacted when you realised what you had said."

The trouble is that I cannot recall any such incidence.
Therefore,I'll have to form a story.

Can you point out consequences of an inadvertent comment that is inane;or a website that can help me along this path.

Your service is appreciated.