Why did I choose my major?

I don't understand how it was that at school I decided to study at medical school, but I was very determined to study it, I think it was when they asked me "how do you see yourself working?" I thought about what my life would be like if I studied engineering and I disliked it despite being good at math, but I did like to see myself helping patients, determining pathologies, researching and performing surgical interventions.

To get here I had to ride a long way. After leaving school, as I mentioned in my first blog, I wanted to study in the Medical school, but my family did not want because my sudden change of thinking from engineering to something with health made them doubt my true vocation, anyway I study for 3 month a nursing major because in that university they allowed the internal change to medicine for being his first year.
At the University of Copiapó I lived in the university home because I could not afford the stay of a normal rent of a room, in the third month the university announced that the internal change cannot be made, which caused many classmates to leave.
After leaving University I went back to Coquimbo and I lived with an aunt, I studied the rest of the year and the year 2019 trying to get the necessary score for Medical school but my NEM made it very difficult despite my good results. I got in a Dentistry major because I couldnt get in to the Medical school. Dentistry was my second option, but every time I think about what my job will be like, all those who said that I don't have the vocation will see the passion with which I will help to many people, all that motivates me every day more. I just want to repay the help I received from everyone who believed in me.