This article explores the temporal nature of language learning in classroom settings through the lens of Conversation Analysis (CA) by drawing on video-recorded interactions from Content and Language Integrated (CLIL) classrooms. It outlines some methodological challenges that the task of documenting language learning in and as observable social interaction poses for CA studies of second language (L2) learning and proposes that learning has typically been described as either a situated activity (in cross-sectional studies) or a series of intermediate achievements (in longitudinal studies). The empirical analysis focuses on interactional instances in which students observably invoke and describe their earlier learning activities or achievements as part of some ongoing classroom activity, either in whole-class or peer interaction. It is argued that such instances of a retrospective orientation to learning offer empirical materials for examining learning trajectories from a participant's perspective, how connections between moments and social domains separated by time and space are forged, and how resources are accumulated, recalibrated, and put to use. The focal interactions also raise conceptual implications for the ways in which learning is both situated and transferable, as well as methodological implications for how retrospection can best be rendered analytically accessible by way of a CA approach.