John's hit: endless shock to follow reprimand (6,3)

'john's hit' is the definition.
I know nothing about this answer so I cannot tell whether it can be defined by this definition.

'endless shock to follow reprimand' is the wordplay.
'endless' means to remove the last letter.
'shock' becomes 'mane' (mane can mean a mass of hair).
'to' says to put letters next to each other (I've seen this in other clues).
'follow reprimand' becomes 'rocket' (I can't explain this - if you can you should believe this answer much more).
'mane' with its final letter taken away is 'man'.
'man' put after 'rocket' is 'ROCKET MAN'.

Can you help me to learn more?