Twice I’d make younger rock, seriously (3,3,7,2)

I believe the answer is:

are you kidding me

I'm a little stuck... Click here to teach me more about this clue!

'twice i'd' is the definition.
I know nothing about this answer so I can't tell whether this works.

'make younger rock seriously' is the wordplay.
I cannot quite see how this works, but
'make' could be 'are' (I've seen this in another clue) and 'are' is found in the answer.
'younger' could be 'kid' (I've seen this in another clue) and 'kid' is located in the answer.
This may be the basis of the clue (or it may be nonsense).

Can you help me to learn more?

I've seen this clue in the Sydney Morning Herald.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.