@wolf1231: Cheesy as it may sound, the best thing about being a psychologist is helping people. In sport psychology in particular, we try to help athletes with the mental side of their game so that they can improve their performances in sport and so that they feel better about themselves. When athletes report back to you after a session that they played really well in competition and that they feel better about themselves, there’s no better feeling!
I would say that it’s because it gives you the chance to do so many different things. For example, my PhD was on how people move their eyes an what parts of the brain control that. My current job is about how people can change the way they walk depending on their personality or how attractive they are, but I’m also starting to get interested in how playing video games affect us when we’re growing up! I’ve no idea what sort of psychology I’ll be doing in 5 years time, and I find that really exciting!