A joke is like a frog
When you dissect it, it dies. Get it? Just like a frog dies when you dissect it, so does a joke when you explain it. Basically, the frog is used as an analogy, to help people understand that jokes shouldn't be explained, because the joke will die, or more specifically, become unfunny. So, just like when a frog dies when you dissect it, so does a joke when you dissect, or explain it.
Best explanation of Star Wars
The story of an orphaned boy who becomes radicalised after a military strike kills his family. He is indoctrinated into an ancient religion, joins a band of rebel insurgents, and carries out a terrorist attack which kills 300'000 people.
A kid asks his dad, "Dad, what is sex?"...
The dad is shocked. He goes into an internal struggle of whether to scold him or to tell him. Finally he decides to tell him and gives the kid the most eloquent explanation of sex complete with foreplay techniques and sex positions. The kid frowns after he's done and asks "So what do I put on the school admission form?"
A man wakes up after a heavy night of drinking to his wife happily cooking breakfast.
Confused, he approaches his daughter for an explanation of last night when he arrived home. "You kicked in the door when you couldn't get your key in the lock, fell through the table and broke it, and pissed your pants." "Jesus! So then why the hell is she in such a good mood?" "When she tried to take your pants off to wash them, you slapped her hand away and said, 'Get your hands off me! I'm married!'"
I got arrested for illegally downloading Wikipedia in its entirety
Before I got arrested I said "wait I can explain everything'
My son just asked me where poo comes from, I gave him a detailed explanation, where he then stood in stunned silence.
Then he asked, “What about Tigger?”
My three year old daughter asked me, “Where does poo come from?”
I was a little uncomfortable but decided to give her an honest explanation. So I said, "You just ate breakfast, yes?"
"Yes." she replied.
"Well, the food goes into our tummies and our bodies take out all the good stuff, and then whatever is left over comes out of our bums when we go to the toilet, and that is poo."
She looked a little perplexed, and stared at me in stunned silence for a few seconds and asked, "And Tigger?"