It is not customary to discover oneself in the practice of one's chosen profession. Take an introductory gerontology course. Talk to people who are working in the field of aging. Ask them why they chose this field, what they do, and how they like their work. The Association for Gerontology in Higher Education offers several articles about careers and jobs in the field of aging.
Some professionals work directly with older persons.
National Institutes of Health. Rick Martinez, M.D. Internist. National Institutes of Health. Daniel O'Neal, R.N. Gerontological nursing specialist. American Nurses Association.