What is the main conflict in The Dead Zone by Stephen King?

"The Dead Zone" by Stephen King is the story of Johnny Smith. Johnny starts out as a happy child who enjoys playing in the wintry outdoors in Maine. At six years old, Johnny's only concern as well as his only dream is to learn how to ice skate backwards. Many of the neighborhood children are playing on the local pond, skating and playing hockey. The kids are separated by age. The older kids play hockey on one side of the pond and skaters stay to the other side. There is an accident and Johnny is knocked to the ground, hitting his head so hard that he blacks out. After a few minutes, Johnny seems to be relatively okay except for a knot on his head. The only peculiar thing is that Johnny tells one of the chaperons "not to jump it no more" and something about a battery and an explosion. Everyone thinks the comment is confusion from the bump on the head. A few days later, the neighbor jumps his old truck once again and there is an explosion, shooting battery acid into the man's face. No one recalls Johnny's prediction.