In Taiwan, older adults over the age of 65 made up 12.51% of the population in 2015, causing the government to promote older adult education to help achieve active aging. As a result, more elderly people have attended learning activities and applied new skills to volunteering. The researcher conducted focus group interviews with 93 older adults from 13 service learning groups to illuminate this process of transforming from learner to volunteer. The findings are as follows. (a) The retirees and empty-nesters undergo discovery during the learning process in order to become learners. (b) These learners then become volunteers through the support from teachers and key persons, through the desire to share learning outcomes, and through answering the call to serve others. (c) The transformative learning rewarded the older adults with improved physical, spiritual, and mental health, as well as gratitude and a new sense of meaning in life.