Methods for managing contents of multiple digital documents for individual users, to generate aggregated documents from multiple documents and/or create associations among multiple documents, based on the user's interactions with multiple digital documents. A document content aggregation method can, on a personalized basis, aggregate contents from multiple digital documents into an aggregated document based on a user's past interactions with the documents. The aggregation is based on a content importance score calculated from the user interaction pattern. A document association method can, on a personalized basis, create associations among multiple digital documents based on the user's past interactions with the documents. Two documents are deemed related if there is a user interaction pattern where the user interacts with both documents with a predetermined time interval from each other. When displaying one document, link icons are displayed to allow the user to directly navigate to the related documents.