Someone who lets their past failures and/or past pains prevent them from doing something for fear of getting hurt or other unpleasantness. An act of cowardice that is derived from past failures or shortcomings. Or anyone who has let failure prevent them from trying at least one more time
Combination of "An elephant never forgets." and "Yellow bellied coward."
James is acting like a yellow elephant for not asking that girl out just because he just got dumped.