why become a doctor?

I guess it had to do with joining as a human being a unique profession which is given by society tremendous challenges, responsibilities and permissions to other humans and which is given to noone else. We can hold the comfort but also the life of others in our own hands.
There is the good feeling from doing good to someone but also the wonder and excitement (even to the point of raising gooseflesh) of making emotional and spiritual contact with your patient.