Development is a process of creating actual time-course of movement out of possible ones—both of the future and of the past. This focus was central for the original notion of “zone of proximal development' (ZPD—Vygotsky)—yet it has not been developed further since 1930s. Human beings operate in-between the constructions AS-IS, AS-IF, AS-COULD- BE and AS-I-WANT-IT-TO-BE. Developmental psychology has mostly dealt with the first two of the constructions (AS-IS < > AS-IF), avoiding the set of possibilities (AS-COULD-BE) and desirables (AS-I-WANT-IT-TO-BE). The recently introduced Trajectory Equifinality Model (TEM), created by Tatsuya Sato and his colleagues, makes it possible to consider both imaginary, possible, desired, and real components of the developing structure in its progression. In this article, I give a theoretical account of the process structure of such coordination of the past and future and of the possible and the actual.