Why does having lost his mother give Julian inner strength?

The View From Saturday is a children’s novel set in a town called Epiphany. It tells the story of Julian Singh and his three friends Noah, Nadia, and Ethan, who are part of a group called "The Souls." Their sixth-grade teacher, Mrs. Olinski, chooses them to represent her class in the Academic Bowl competition. The Souls face more competitions and win.
Being an Indian boy with a British accent, Julian often gets bullied and teased in school. Julian’s mother died when he was a younger boy. His father is an innkeeper in Epiphany, and it is here that Julian and his friends, The Souls, get together for tea every Saturday at Sillington House.
The Souls try to make Mrs. Olinski's life happier and to encourage her. However, it is Julian's kindness that is notably recognized by Mrs. Olinski. Although other students play pranks on her because she is paraplegic, Julian sticks up for his teacher.
Even though Julian suffers from his own set of insecurities because of his skin color and accent, he gets full support from Ethan, Noah, and Nadia. The Souls often offer support, and this strengthens him, despite the loss of his mother.
The Souls all come from challenging backgrounds, but they succeed where others would expect them to fail. In being asked why Mrs. Olinski chose The Souls for her competition, she declares that these four children always treat each other with respect and kindness.
It is Julian's father, Mr. Singh, who states that "it often takes more courage to be a passenger than a driver." He is referring to Mrs. Olinski’s paraplegic condition and the difficulties that come with giving up control over one’s life to others. Mr. Singh also states that Julian has learned to be a passenger in life and appreciates all that life offers. In support of his son, Mr. Singh says that Julian has a gift of being able "to regard each port of call as part of a journey and not as a destination." Julian doesn’t have the ability to control his surroundings, but he doesn’t let that stop him from being kind to others.