Two adults viewing the same scene tend to fixate overlapping parts of it. This has led to decades of modeling average fixation densities. However, individual fixation patterns deviate from this in highly reliable ways. How do we get to this point? Do young children fixate scenes in stereotypical ways and acquire individual preferences over time? Or is children’s gaze idiosyncratic before becoming more canonical? We present eye-tracking data from >6,500 subjects from 5-72 years of age, freely viewing 40 complex scenes. This large dataset allowed us to trace the development of individual differences by estimating pairwise correlations of fixation patterns, separately for age groups of two years. We find that preschool children tend to fixate fewer elements of a scene and agree on those to almost the same degree as adults do. Then, image exploration and the number of fixated elements increase for more than a decade. In parallel to this, pairwise similarities rapidly drop, the gaze of children becomes increasingly idiosyncratic until age 14. Then, the trend reverses, patterns of gaze become more and more similar despite a continued increase in exploration. Pairwise similarity only plateaus from the early twenties, showing that the degree to which adult gaze is canonical takes decades to develop. I will speculate on the reasons for this protracted development and its potential relationship to scene understanding.