How is it like to be an oncologist, education ? Patients ? The expense ? Emotionally ?

An oncologist takes the same training as any other medical doctor, which means a college major in a science, which will lead to medical school. Following medical school is the internship and residency, so you're looking at ten to twelve years of schooling. When you become a "resident," you begin training in a specific medical field. You'll work with an oncologist associated with a hospital, continue your studies, and become very knowledgable in that specialty. A good physician never stops studying, so even after you begin your practice, you'll be reading medical journals and trying to keep up on the latest techniques, medicines, and practices. Oncology can be a particularly challenging field of medicine, since a number of your patients simply cannot be helped. All you will be able to do for them is make them comfortable, support their families, and give them advice about "end of life" care. If you are the kind of person who is sensitive enough to see the important contribution which this makes without feeling that you are "failing" because your patients don't get well, then this is possibly a field for you.