Condensed matter physics or material science is a field encompassing very diverse research topics from some fundamental issues to very technical problems. As such, nothing can coherently define the enduring themes of the whole material science. Nevertheless, I will argue with some reservations that it is a very fruitful exercise to examine materials from the perspective of structure and dynamics using neutron scattering. As example, I will present two scientific problems I have worked, which include a metal-insulator transition in Tl2Ru2O7 [1] and a giant spin-lattice coupling in multiferroic RMnO3 [2]. I will also illustrate certain aspects of magnetism [3, 4] in the era of nano science and reflect on my own experience for the past 7 years of building a large research infrastructure of inelastic time-of-flight neutron spectrometer at a Korean research reactor, HANARO. In the second part, I will cover several research topics, which I have my eyes on at the moment, and try to convey to the audience lessons I have been learning throughout my career.

[1] Seongsu Lee, J.-G. Park, D. T. Adroja, D. Khomskii, S. Streltsov, K. A. McEwen,
H. Sakai, K. Yoshimura, V. I. Anisimov, D. Mori, R. Kanno, and R. Ibberson Nature Materials 5, 471 (2006)
[2] Seongsu Lee, A. Pirogov, Misun Kang, Kwang-Hyun Jang, M. Yonemura, T. Kamiyama, S-W. Cheong, F. Gozzo, Namsu Shin, H. Kimura, Y. Noda, and J.-G. Park
Nature 451, 805 (2008)
[3] Novel features in the relaxation times of Mn12AC, C. Paulsen and J.-G. Park, Quantum Tunneling of Magnetization-QTM'94, edited by L. Gunther and B. Barbara (Kluwer Academic Publishers, 1995, The Netherlands)
[4] Jongnam Park, Kwangjin An, Yosun Hwang, Je-Geun Park, Han-Jin Noh, J. Y. Kim, Jae-Hoon Park, Nong-Moon Hwang, and Taeghwan Hyeon, Nature Materials 3, 891 (2004)