One of the reasons that I love psychiatry is that you get to focus on why people do the things that they do that may be causing their problems - is it their personality style, their personal history, their particular pathology or most likely a combination of all of the above and other things? It is all an important part of the diagnosis.
In GP you can look at this briefly, but it often is not the focus of the consultation - people want to fix the problem, preferably with a pill or quick-fix, and then move on in the space of a 15-minute consultation, possibly with a follow-up in a week's time if the antibiotics haven't worked well enough.
You get to manage chronic and serious illness, but often with the assistance of specialists who ultimately call the shots.
It is more about managing the lives and basic healthcare of your patients. If you love looking after the whole healthcare of a person and managing their care, GP would be your cup of tea. If you love sitting in an office and telling people how it is, and how to manage their lives, make steps to lose weight, take multivitamins before they get pregnant, get their flu shots and manage colds, look in ears, test for more serious illness and then refer when you find something, you might enjoy it.
I'm a little bit too avoidant and obsessive to be happy or comfortable doing this. I also like being more specific in my focus.
I like understanding my patients and spending time on this. I also like looking at the specifics of pathology in imaging and pathology slides. It is probably because I love understanding why things happen the way that they do, and observing changes, that I enjoy these specialties. I know that they are quite different from each other, and that is okay. I think it is more important to look at what I enjoy and am good at and why I like it than make any decisions at the moment. Hopefully this will lead to doing something that I'll be happy with for the rest of my working life.
Knowing myself, I just wouldn't be happy as a GP, which is a bit of a shame on one hand, but a relief on the other. :)