Galaxy Formation Now and Then

I review the current state of our understanding of the galaxy formation and evolution process from the modeler's perspective. With the advent of the cold dark matter model and the support of fast computers and advanced simulation techniques, there has been considerable progress in explaining the growth of structure on the largest scales and in reproducing some of the basic properties of galaxies and their evolution with redshift. However, many properties of galaxies are still only poorly understood or appear to be in conflict with the prediction of the cold dark matter model. I discuss in what direction the next generation of galaxy formation models may go and why a large space-based optical-UV telescope could be critical for the calibration and testing of these advanced models.