"Cassidy" is a song imbued with a sense of personal connection and reflection, named after Cassidy Law, the daughter of a Grateful Dead crew member and Bob Weir's former housemate. The lyrics also draw inspiration from Neal Cassady, a figure linked to the Beat Generation and the Acid Test scene that helped birth the Grateful Dead. This blend of influences creates a narrative that touches on themes of lineage, community, and the passage of time, further deepened by elements inspired by the death of Barlow's father. It plays like a contemplative journey through personal history and shared cultural touchstones.