Emotions are a corrupting bitch but you can trigger them. They are responses to interpreted environment so if you know you;re somewhere safe you feel good. If you know you are somewhere unsafe, you feel bad. As all knowing is actually just belief, emotions are flexible and can be programmed and controlled by redefining situations.

E.g. you are told that your birthday cake is delicious and home made - you feel good.
you are then told that it is suspected to contain rat poison - you feel bad feelings about the same cake without ever tasting it. You are merely reacting to an object and situation and its relevance to you.