When Clark was a kid, the Kents warned him not to use his powers on anyone because he might hurt them real bad. They never imagined that would leave young Clark afraid to stop the man who wanted to hurt Clark real bad.

Adult Clark *knows* it wasn't his fault, intellectually he understands that. But that doesn't stop him from hating himself for not fighting back when all it would have taken was a flick of his pinky. And more than anything he fears his newly won friend learning that he wasn't even able to protect himself. But the truth comes out and its Bruce who helps him, Bruce who shows him how to forgive himself.