Photon Science penetrates a new range of scientific disciplines from materials science, physics, geoscience, chemistry, biology over nanotechnology to energy science. This is the strength of our facility at scientist level. But, it also makes it difficult to identify our contribution to scientific outcome as well as industrial application at facility level. The days are gone when "small science at large facility" could be pursued as curiosity-driven research with facility users. Large facility is, now, called into question it's raison d'etre as an usher of technology-driven science. One way to survive as a must-have for society is to promote "challenging science at large facility". In my talk, I shall overview what I learned and what I did at SPring-8 with the hope of animating some discussions with the audience.