Interest is the need for certain information. Propensity is a predisposition to certain activities. Many people are interested in medicine, but not all of them have a penchant for the work of a doctor and a nurse. Interests do not always coincide with inclinations, and this often turns into a tragedy. As often happens, fascinating stories about doctors lead young people to medical institutes, but after a while they realize that they were mistaken with a door, that they could not master many difficult terms, and indeed medical duties themselves. We have to change the profession. Usually such people say that they do not have the ability to medicine.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.