Calmness before stupid coming through Surrey's borders? (8)

I believe the answer is:

serenity

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

'calmness' is the definition.
(I know that serenity is a type of calmness)

'before stupid coming through surrey's borders?' is the wordplay.
'before' becomes 'ere' (poetic term).
'stupid coming' becomes 'nit' (I can't explain this - if you can you should believe this answer much more).
'through' is an insertion indicator (inserted letters go through the word).
'borders?' says to hollow out the word (remove centre letters) (only the edge or border letters remain).
'surrey' with its middle taken out is 'sy'.
'ere'+'nit'='erenit'
'erenit' put into 'sy' is 'SERENITY'.

Can you help me to learn more?

(Other definitions for serenity that I've seen before include "Peace of mind" , "Peacefulness" , "Peace, tranquillity" , "Tiny seer in state of repose" , "Peace and quiet" .)

I've seen this clue in The Independent.

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.