The author’s reasoning for each is this:
Capacity for pleasure - When you engage in an activity you enjoy, you probably have more fun than a neurotypical person would doing the same activity. Because all your emotions are experienced in an intense way, you get the benefit of extreme joy.
Courage and optimism - When you feel your emotions so intensely, you are less apt than a neurotypical person to use self-talk to regulate the level of arousal. Because you may not always think about your own reactions to events, your passion may at times cause you to persist in your pursuit of something despite “rational” reasons to stop. There is less communication between the thinking and emotional brain, which can result in incredible courage and optimism.