One endeavor you may wish to take up is an organized assault upon the great books. Over on this website is a 10-year plan for working through many great works. You can probably polish off the first three years or so this summer, if you work at it.
An added plea: if you decide to do this, and you are on or near campus, please keep requesting the relevant volumes from the “Great Books of the Western World” series edited by Mortimer Adler. All of these volumes are currently being held in the automated-retrieval system at the USU library (the “BARN”), and the best way to get these volumes shelved in the public stacks is to keep requesting them. It’s easy: just look up the work from the online catalog, and click the “request” button, and the book will be waiting for you at the circulation desk. The great books really don’t belong in a barn!