For some people nursing is a calling. For some people it isn't. The majority of nursing positions involve establishing nurse-patient relationships, i.e. direct patient contact. If you feel annoyed by your patients' requests/complaints, can't tolerate their lack of independence, find dealing with bodily fluids offensive, are generally annoyed by patients families, and don't care about furthering your patient's well-being and advocating for your patient, well, that's a bad sign if you are planning in working in direct patient care. Patients and their families do pick up on these things, and a bad situation is created if the patient/family do not trust the nurse. So no, you don't need to be called to nursing, and many nurses aren't, but you do need to be willing to listen to patients and their families, to try to understand them, and to be motivated to do your best to take care of them.
Smoothkeys, you mentioned a concern about whether you would be as motivated to take care of strangers as you would your own family. Nursing school will give you an initial clue as to how you feel about taking care of strangers, and to your level of motivation. Working as an aide or PCT will also give you some idea.
Many nurses do not find their frustrations in nursing are primarily related to taking care of patients. Some people find the demands of the whole corporate health care machine intolerable. For anyone considering nursing as a career, I really suggest testing the water as much as possible before investing a lot of time and money in a profession you may hate. Right now there is no shortage of nurses, and there are nurses who hate their jobs and hate taking care of patients.
There are nursing jobs
that don't involve direct patient care, but often they require bedside nursing experience. There are also jobs working for insurance companies, but if that is your end goal before becoming a nurse, why put yourself through the stress and expense of nursing school? If one's goal before starting nursing school is to find a nursing job with minimal patient contact, I would suggest another major.