LitCharts assigns a color and icon to each theme in Wonder, which you can use to track the themes throughout the work.
The Difficulty of Kindness
Independence and Growing Up
Status and Bullying
Identity
Parenting and Guidance
Summary
Analysis
Mr. Browne's final precept is to "follow the day and reach for the sun." He includes a note on the board asking students to send him a postcard with their personal precept on it.
The final precept makes it clear that the kids aren't at the end of their journeys of growing up; they'll need to keep reaching as they continue to mature.