Research on coalition negotiations after general elections in parliamentary systems usually focuses on the parties’ utility maximization as corporate actors. However, the most recent process of government formation after the German general election in 2017 followed a different type of logic and led to an outcome unlike that of other coalition negotiations. Regarding policy seeking, office seeking, and vote seeking, the outcomes of both the exploratory talks between Christlich Demokratische Union (CDU)/Christlich‐Soziale Union (CSU), Freie Demokratische Partei, and the Greens and the negotiations between CDU/CSU and Sozialdemokratische Partei Deutschlands are at least partly irrational from a cost–benefit analysis. This article examines the formation of Germany’s government in 2017–2018 and reveals the paradoxical outcomes of each phase of the negotiations. Empirical data to underpin the argument stem from interviews with negotiators and statements of direct participants in the formation of the coalition. Instead of the parties’ utility maximization, negotiations were largely dominated by intraparty conflicts, in which individual interests and personal trust rather than partisan unitary programs were most relevant to the negotiation process and outcome. Our work answers the question of why the grand coalition was unexpectedly renewed in the end—contrary to what might be predicted based on established theories of coalition building. The observations and conclusions set forth are of general interest not only for future coalition negotiations in Germany but also for other European parliamentary democracies facing increasing party fragmentation. Most importantly, the analysis yields insights into negotiations undertaken in the absence of rationalist behavior.