In case studies of two first-year elementary classroom teachers, we explored the influence of informal science education (ISE) they experienced in their teacher education program. Our theoretical lens was identity development, delimited to classroom science teaching. We used complementary data collection methods and analysis, including interviews, electronic communications, and drawing prompts. We found that our two participants referenced as important the ISE experiences in their development of classroom science identities that included resilience, excitement and engagement in science teaching and learning--qualities that are emphasized in ISE contexts. The data support our conclusion that the ISE experiences proved especially memorable to teacher education interns during the implementation of the No Child Left Behind policy which concentrated on school-tested subjects other than science.