In the end, you often discover you feel totally rebellious (6)
I believe the answer is:
unruly
'rebellious' is the definition.
(I've seen this before)
'in the end you often discover you feel totally' is the wordplay.
'in the end' says to take the final letters.
The last letters of 'you often discover you feel totally' are 'UNRULY'.
(Other definitions for unruly that I've seen before include "Disobedient or disorderly" , "Not disciplined" , "Disobedient and disruptive" , "Noisy and undisciplined" , "'Boisterous, disobedient (6)'" .)