Over the first two school years under the COVID-19 pandemic, K-12 enrollment in public schools decreased dramatically--with losses concentrated among the youngest students--and the pandemic has had historically unprecedented effects on available learning opportunities. Little is known about where these students went and what learning environments they are experiencing. Understanding the diverse character of these effects has not been straightforward. The pandemic has complicated the comparability of many conventional education indicators and conventional data from administrators, and surveys on student experiences are often available only after long delays. The data reveal that two of the primary explanations for the public school pandemic exodus are an increase in homeschooling and a decrease in the school-age population. But these two trends cannot explain the entire enrollment drop. The large amount of public school enrollment loss that, in many states, cannot be explained by changes in nonpublic enrollment and demographics suggests the possibility of other developmentally relevant behaviors (e.g., kindergarten skipping, unregistered homeschooling, and truancy) that merit further research.