How do children conceptualise their own development? From their point of view, what serve as constraints for their movements in time and space? The theoretical framework of the experiment described here was a cultural historical first person developmental perspective. The concept of transition is here put in use to capture the children's experience of their movements with or against a dynamic, inviting and demanding socio-cultural landscape over time. An interpretation of children's experience of their developmental timing with temporalities of the childhood landscape is presented. (Contains 6 figures.) [Abstract is presented in both English and French.]