Lastly, I want to thank Martijn. For your great support and love. You were always there to listen to my stories and when I needed to talk about my frustrations, and you helped to find solutions to every problem. You asked the right questions and put me on the right track again. You were also willing to read and comment on my texts and were genuinely interested in my research. We could share our experiences about being a PhD, although we also frequently saw that this meant something different in the US than in The Netherlands. Most importantly, we celebrated and laughed together a lot, and you cheered me up when I needed it.