Garth Callaghan doesn't know how long he has to live. But he can be certain of one simple thing: No matter his fate, his daughter, Emma, will find a handwritten note inside her lunchbox each day until she graduates from high school.

Cancer has given Garth Callaghan a new purpose: to inspire parents to connect more with their children even in small ways, as he has done before and since his diagnosis by tucking a napkin note into his daughter's lunch every day.

Every morning as he packs Emma's lunch, Garth adds a little surprise: a "napkin note"--a short, tender message to convey...