Gain wisdom breaking naval red line (4,3,5)
I believe the answer is:
live and learn
'gain wisdom' is the definition.
I know nothing about this answer so I can't judge whether it can be defined by this definition.
'breaking naval red line' is the wordplay.
'breaking' is an anagram indicator.
'naval'+'red'+'line'='navalredline'
'navalredline' anagrammed gives 'LIVE AND LEARN'.
Can you help me to learn more?
(Other definitions for live and learn that I've seen before include "Profit from experience" , "Keep finding out new things" .)