The broadness of a theme allows its meaning to change. You started out wanting to read more books, but maybe as you went on, you realized academic papers are where it's at. Or that reading reading just doesn't work for you and listening reading is the way to go. You're still on theme.
Instead of resolutions, we set an overall idea of how we would like to approach each year or season. This becomes almost like a guiding principle for our work and/or personal lives for that period. For example, we both have used the theme ‘The Year of Less’. For Grey this meant a year of less travel and less commitments; for Myke it meant starting no new projects for a year.