With Last Stop on Market Street (Putnam, 5–8 years), author Matt de la Peña and illustrator Christian Robinson take readers on a bus journey through the city — along the way exploring a young boy's warm relationship with his nana, her sunny outlook on life, and their interactions with the diverse people they encounter. We chatted with Christian about the book’s illustrations and his inspiration behind them.

1. Did you have a special relationship with your own grandmother?

CR: My grandmother raised my brother and me. She made sure I always had a place to call home. Growing up, our resources were limited. My grandmother taught me how to make the most of whatever I had and to count my blessings.

2. Are the people on the bus imagined or are they from real life? Did you have their backstories in mind as you created the illustrations?

CR: I ride the bus a lot and it never gets boring. The people in the illustrations are real, and I wouldn't even say exaggerated — although I haven't ridden next to a lady with butterflies in a jar yet. So far I've sat next to a woman with a flopping fish in a paper bag and, another time, a guy with a live chicken in a cardboard box (with breathing holes, of course). Each character does have his or her own story. It's the meeting of so many different storylines that makes riding the bus so entertaining. Where did all these people come from and where are they going?

3. Do you have a favorite bus route for sight-seeing or people-watching?

CR: The 22 Fillmore bus in San Francisco (where I live) is always a hoot. I think it's because it passes through a wide range of neighborhoods with extreme socioeconomic differences. On this route you can have someone sitting on your right talking on the latest iPhone, and to your left a homeless person asking you if they can make a call on your phone.

4. What do kids learn from helping others in need?

CR: Empathy. I think children innately have the ability to understand and share the feelings of another. Of course, like all things, with practice you can cultivate your ability to be even more empathetic and compassionate toward others.

5. CJ ponders "how his nana always found beautiful where he never even thought to look." Where do you "find beautiful"?

CR: I wouldn't know where to begin. Sometimes I think I might overdose on the beauty life has to offer. Part of the reason I find being an illustrator so fulfilling is that I get to record and communicate my experience of the beauty in the world.

From the May 2015 issue of Notes from the Horn Book.