Emotions get real and you cannot control them. They are what they are. Then, we start to love again. Events are unpredictable. Emotions are undependable.
Enthusiasm is undepletable.
Enthusiasm is a wonderful word. It actually comes from the Greek root of 'enthuas', which means 'in God'. Our enthusiasm comes when we are in God. That's where enthusiasm comes from. When we are plugged into Him and His power, it's undepletable.