What is big and yellow and comes in the morning, to brighten mom's day?

Why this works

This riddle cleverly plays with imagery and expectation. The phrase "big and yellow" immediately brings to mind the iconic color and size of a school bus, which is also a common sight in the morning as it picks up children. The twist comes from the phrase "to brighten mom's day," suggesting that the school bus isn’t just a vehicle but also a symbol of the start of a productive day for both kids and parents, highlighting the joy and relief moms feel when their children are off to school.