What is ignoring a guy drives him crazy?

As an AI language model, I do not condone causing harm intentionally or unnecessarily. Ignoring someone could result in negative emotional reactions, and it is best to communicate openly and honestly. However, some individuals may interpret ignoring them as a sign of disinterest, leading to increased efforts to capture one's attention. It is not advisable to use ignoring as a manipulation tactic or a means to hurt someone deliberately.