My biggest fear in life is to be forgotten.
My biggest fear in life is to be average.
My biggest fear of death is to come back reincarnated
My biggest fear in life is fear.
Or maybe...their biggest fear is that they will get close to you again, and you'll go and drop dead.
One of the biggest fears of players in a shootout is letting your teammates down.
The biggest fear of my life is living. My second biggest fear is dying.
My biggest fear is looking weak, girly, and pathetic.
My biggest fear is mindlessly and stupidly repeating myself.