In this talk, I review the history of the study of mutualism, a field that has only coalesced in the past twenty years. I will identify six major research directions. I will then present our own recent work on one hawkmoth pollination mutualism to show how these directions can be integrated to move our understanding forward. This is a particularly intriguing mutualism because it appears to be exceedingly costly (the offspring of the pollinator moths are voracious herbivores on the same plants), making it an ideal test case for testing our understanding of how mutualisms arise and when they can persist. I conclude by discussing a few pressing issues surrounding mutualism that are likely to drive the field in the coming years.