Nature of science (NOS) is considered an important aspect of scientific literacy. Despite efforts in guiding school students to develop more adequate NOS views, little is known about the long-term retention of students' post-intervention views. Retention of adequate NOS views is needed for functioning as scientifically literate citizens. Moreover, little is known about the long-term impacts of NOS interventions, important for evaluating their potentials in contributing to the preparation of scientifically literate citizens. This study reports on the results of four case studies through which the researcher examines the developments of four students' NOS views over a 13-year period. More specifically, the study sheds the spotlight on students' long-term retentions of their NOS views as well as the long-term implications of a NOS intervention. During the academic year 2006--2007, the researcher--a high school science teacher at the time--had designed and taught an Honors Biology course, using a consensus framework of NOS as its focus, contextualized within rich science content, and embedded within an explicit--reflective method. The researcher analyzed existing data from 2006-2007. He also collected and analyzed new data in 2019. The findings of these case studies show that the four students benefited from the NOS intervention in the short term, yet their patterns of retaining their NOS views were quite different in the long term. The results showed that it is not possible to assume that a NOS intervention with the characteristics described above and delivered within the setting of an Honors Biology course would necessarily have a long-term impact on students' views of NOS. The findings of this study are discussed in terms of "who" benefits from NOS instruction at the school level. Questions are generated and hypotheses are proposed for further investigation.