NextMe-800: Anticipating Personal Behavior from Months of Egocentric Video

We often plan ambitiously yet act habitually and wonder, in retrospect, whether we would have planned differently had we known what we would actually do. Hindsight offers a valuable perspective on past decisions, although we often wish we could have simulated hindsight at the moment of choosing. If a system could generate plausible trajectories from one's personal history, such previews might help people formulate more realistic plans and make better informed decisions. We introduce NextMe-800, an approximately 800-hour first-person dataset from one volunteer over 126 days with 1 Hz images, gaze, and audio, captioned at five hierarchical abstraction levels from atomic actions to major activities. We formulate personalized action anticipation as open-vocabulary $K$-step sequence prediction and construct NextAct, a 1,500-point benchmark combining NextMe-800 and EgoLife for within- and cross-person evaluation. Using an embedding-based soft edit distance as the metric, we evaluate how well different models can anticipate personal behavior and how prediction scales with context length. NextMe-800 and NextAct provide a months-long resource and evaluation framework for studying how far ahead personal behavior can be anticipated from egocentric observation.