Although I am keen on medicine, I want to do well on UMAT as I want to keep options open. It does not essentially mean I just want to do Med because I have been looking at other courses such as doing Nursing and I'm keen on teaching too.
As of now, my focus is leaning to medicine since I want to help patients both in a practical sense as well as through my clinical research. My focus on leaning to Med has changed but I guess going to JMSS might change that view 
Going into a career in Medicine, I know you have to be emotionally ready. It's one thing to say that you want to do Med because you enjoy helping people but it's not use if you're hand is quivering with fear due to your emotions. That's one of the big things that you need to take a grip on but more on top of a career in Med... it's quite a long journey which involves absolute dedication (which is the same for all courses).
UMAT is really only required for Medicine and Dentistry - so there really isn't much of a "keeping options open" there
Wanting to help people in a practical way - well that's something that's very broad and that's something that a lot of professions do - it's not unique to Medicine even though, for some reason, that is portrayed as the case.
It's not about just being emotionally ready, it's about making sure that you actually want to do Medicine, it means that you want to do Medicine for the right reasons and you don't have a doubt in your mind that it is the path you want to take. And yes, it's a long journey which requires dedication, but it is not the same for all courses, many courses, you are out and working after three years, do you know how long you'll be learning for if you want to become a doctor?
I think, you know, this really reinforces my point that students usually don't really know what they want to be when they grow up and it's understandable why, many students choose courses such as Commerce, Medicine, Engineering and all that and have no clue what those courses actually teach and how they will get to their dream. I'm not saying you want to do medicine for the wrong reasons (because only you know those reasons), but what I'm saying is, make sure it's what you want to do - don't be influenced (unknowingly) by external pressures.