My mind as wandering shows energy and enthusiasm (8)
I believe the answer is:
dynamism
'energy and enthusiasm' is the definition.
(being dynamic or enthusiastic)
'my mind as wandering' is the wordplay.
'wandering' is an anagram indicator.
'my'+'mind'+'as'='mymindas'
'mymindas' is an anagram of 'DYNAMISM'.
'shows' is the link.
(Other definitions for dynamism that I've seen before include "Energy" , "Forcefulness" , "Full-of-energy quality" , "Pizzazz" .)