Storytelling is an act of cruelty. We are cruel to our characters because to be kind is to invite boredom, and boredom in storytelling is synonymous with big doomy death-shaped death. So: be cruel to your protagonist. Rob him of something. Something important. Something he needs. A weapon. An asset. A piece of knowledge. A loved one. A DELICIOUS PIE. Take it away! Force him to operate without it. Conflict reinvigorates stale stories. New conflict, or old conflict that has evolved and grown teeth.