Answer:
"I was struggling to figure out how lightning works, but then it struck me."
Step-by-step explanation:
let’s take a look at the meaning of pun:
a joke exploiting the different possible meanings of a word or the fact that there are words which sound alike but have different meanings; making a joke exploiting the different possible meanings of a word.
The word “struck” in this phrase can be interpreted in two different ways, “struck” as in lightning, or “struck” as in having a thought or idea come to mind.
Hope this helps!