Why are people afraid?

There are many reasons why people are afraid, to list them all would be quite impossible. Mostly i believe people are afraid because they have something to lose, such as a life, companionship etc and due to harm or maladies befalling them. Fear can also result due to uncertainty, eg. uncertainty about your future if you do not do well in your exams etc. If you are mentally strong and able to detach yourself from the real world there is no need to fear anything.