Walter Benjamin's thesis about a creative character of childhood is starting point for a text. According to Benjamin childhood can be compared to the dream. A process of growing up recalls awakening. A world that children perceive, however mysterious and unknown, process a fullness that disappears when they grown up. In philosopher's reflection childhood evoke a collection of postcards inscribed in a memory. Freud's metaphor of archaeology illustrates the mechanism of recreating memories is human mind. In this metaphor a concept of afterwardness is essential. Freud interpreted 'afterwardness' as an understanding of traumatic experience, that took place 'too early', but their presence in a consciousness came 'too late'. In the first part of text, two significant children-photographers - Jacques H. Lartigue and Stanislaw Ignacy Witkiewicz are considered as examples of creative power and experimental attempts of childhood. Taken by children pictures of happy past leads us to the nostalgic dimension of photography. Next part is dedicated to Benjamin's idea of collecting postcards and asks a question about a possibility of recreating the past from the images. The dilemma of photographic mediation between the past and present is outlined also in the last part of text where photography becomes a method of analyzing the architectural aspects of contemporary Berlin. A notion of 'afterwardness' is especially useful here. Photographers work as archaeologists of unconsciousness: their revealing of a past reminds 'digging for memories' and its interpretation.