An accurate thought map is created by recording people's many utterances of natural language expressions together with the location at which each expression was made. The expressions are input into a Natural Language Understanding system including a semantic parser, and the resulting interpretations stored in a database with the geolocation of the speaker. Emotions, concepts, time, user identification, and other interesting information may also be detected and stored. Interpretations of related expressions may be linked in the database. The database may be indexed and filtered according to multiple aspects of interpretations such as geolocation ranges, time ranges or other criteria, and analyzed according to multiple algorithms. The analyzed results may be used to render map displays, determine effective locations for advertisements, preemptively fetch information for users of mobile devices, and predict the behavior of individuals and groups of people.