"Forget the former things; do not dwell on the past. See, I am doing a new thing! Now it springs up; do you not perceive it? I am making a way in the wilderness and streams in the wasteland." Isaiah 43:18-20
Are there things from your past that you keep going back to?...
"Because of the surpassing greatness of the revelations, for this reason, to keep me from exalting myself, there was given me a thorn in the flesh, a messenger of Satan to torment me - to keep me from exalting myself!" -Paul, 2 Corinthians 12:7
If I had to guess the enemy's psychologic makeup, I would hypothesize narcissism is a big part of who he is. After all, he thought he could be bigger than God, and he is the epitome of everything bad that exists in all of creation.