Keith Beven is a voice of reason on the intelligent use of models and the subsequent acknowledgement/assessment of the uncertainties associated with environmental simula-tion. With several books and hundreds of papers, Keith’s work is widespread, well known, and highly referenced. Four of Keith’s most notable contributions are the iconic TOPMODEL (Beven and Kirkby, 1979), classic papers on macropores and preferential ﬂow (Beven and Germann, 1982, 2013), two editions of the rainfall-runoff modelling bible (Beven, 2000a, 2012), and the selection/commentary for the ﬁrst volume from the Benchmark Papers in Hydrology series (Beven, 2006b). Remarkably, the thirty-one papers in his benchmark volume, entitled Streamﬂow Generation Processes, are not tales of modelling wizardry but describe measurements designed to better understand the dynamics of near-surface systems (quintessential Keith). The impetus for this commentary is Keith’sPhD research (Beven, 1975), where he developed a new ﬁnite-element model and conducted concept-development simu-lations based upon the processes identiﬁed by, for example, Richards (1931), Horton (1933), Hubbert (1940), Hewlett and Hibbert (1963), and Dunne and Black (1970a,b). Readers not familiar with the different mechanisms of streamﬂow generation are referred to Dunne (1978).