The thing i'm most scared of is "fear" itself. According to Google its an unpleasant emotion caused by the belief that someone or something is dangerous, likely to cause pain, or a threat. Once you first experience fear its with you forever. Its not a disease nor illness, simply a felling of emotion. All people have difference fears. We can not deny that every person feels dead. To my mind, children have many fears, for example they are afraid of being alone in dark place. They ask parents to switch on the light. People who have unpleasant experience in their past, can have many fears in the future, for example, if we have a girl who was bit by dogs
when she become adult, the girl can afraid of dogs. It is natural reaction our memory.