A journey is only one visible episode within a much denser temporal system of routines, relocations, residences, family relations, work, education, transport competence and repeated exposure to distance. The decisive shift is from counting movement as event to reading movement as trajectory. Scheiner’s mobility biography supplies this shift by showing that travel behaviour acquires temporal depth through path dependence: stable habits persist, key transitions interrupt them, and different partial biographies—residential, household, educational, professional—continually modify one another. A forty- or fifty-year mobility record is therefore not a linear itinerary. It is a stratified system in which periods of intense international circulation coexist with years dominated by commuting, family travel, local cycling, repeated returns or one stable base generating hundreds of radial movements. Long duration also changes what counts as evidence. Memory can recover major relocations, family journeys, schools, workplaces, accidents, relationships and recurrent destinations more reliably than precise frequencies or exact distances decades later. The life course calendar formalises this asymmetry instead of concealing it: years become temporal containers in which several domains can be aligned, compared and corrected.
Albrecht, Holz-Rau and Scheiner push the principle further by distributing recall across linked lives. Childhood mobility, especially, is often organised by others before it is consciously authored by the child. Parents choose where to live, when to travel and which forms of transport structure family life; siblings, partners, friends and colleagues later become co-producers of movement. A mobility biography is consequently neither wholly individual nor reducible to memory. It is a relational reconstruction whose confidence increases when recollection, photographs, addresses, institutional records, family testimony and dated project traces converge. Socialisation provides the bridge between early mobility and later competence without requiring a deterministic story. Repeated travel in childhood does not mechanically produce an internationally mobile adult, yet it can normalise certain spatial practices: long car journeys, border crossing, camping, public transport, bicycles, foreign languages, temporary residence and the expectation that distant places can enter ordinary life. Scheiner’s linked-lives formulation is crucial here because it identifies mobility as something learned socially before it becomes an autonomous choice. Later transitions—leaving home, study abroad, work, partnership, professional networks—can reactivate and transform those dispositions. The relation is therefore cumulative rather than causal in a simple sense. Early routines form a repertoire; later circumstances select, intensify or redirect elements of that repertoire. The biographical field is one of sedimentation, interruption and re-use. Everyday recurrence must remain visible within this field. Pooley and colleagues demonstrate that ordinary travel can reveal as much about social organisation as exceptional journeys. A school commute repeated hundreds of times, a bicycle route to a friend, a train between residence and university, or years of travel between home and workplace can generate more embodied spatial knowledge than a single international trip. Such movements register scale, duration, waiting, weather, public transport, road systems, bodily effort and the negotiation of time with others. They also reveal historical change: the meaning of cycling, walking, family car use or independent travel varies with infrastructure and social norms. A long mobility corpus therefore requires at least two registers—discrete movements and recurrent regimes—because collapsing both into one total would destroy the difference between episodic displacement and habitual spatial organisation. This distinction becomes operational in Socioplastics when approximately three hundred known local, national and international movements are treated as a minimum discrete corpus rather than as a finished autobiography. The value of the corpus lies less in the headline number than in the relations it allows to be indexed: first appearances and returns; recurring cities; family, educational and professional phases; changes of transport mode; the emergence of works and series in particular locations; long stable periods that nevertheless generate dense local mobility; and later routes in which movement itself becomes a research method. The archive can therefore map not only where movement occurred but what kind of movement it was, what life domain sustained it, what evidence survives and what later practices emerged from it. The same city may appear first as childhood environment, later as educational node, professional territory, artwork location or comparative field site. Recurrence transforms location into temporal depth. The strongest consequence is methodological. City After City can remain a bounded 2026 empirical sequence while a separate mobility biography explains the formation of the observer without retroactively converting decades of memory into equivalent urban evidence. The long trajectory functions as observer history: it identifies accumulated exposure, learned mobility, repeated geographical comparison, professional spatial training and serial artistic practices that preceded the formal method. This preserves a strict evidential boundary while making formation itself researchable. Mobility biography thus adds to Socioplastics a longitudinal infrastructure for connecting life course, spatial practice, archive and observer formation without confusing recollection with contemporaneous observation. I