““In general, we imagine rivers to be subject to a kind of dynamic equilibrium, largely stable geologic features, with processes like regional incision or subtle shifts in mountain building causing short- and medium-term variation around some slowly changing mean condition, but in fact it is far more common to see dramatic change over short periods, with long periods of stability between in what geologists refer to as 'dynamic metastable equilibrium.' It is the same with families, memory, the history of a person's life, what we believe to be true.””
