The fifth of the five "1s" of Romanticism that is represented in the poem "Because I could not stop for Death" is the focus on the individual and subjective experience.
The poem describes the speaker's personal journey with death, as the speaker reflects on her own feelings and emotions as she journeys with Death. The speaker describes her personal experience of death as a "gentleman" who "kindly stopped for me" and takes her on a journey to eternity. This emphasis on the personal, subjective experience is a hallmark of Romanticism, as the poets often explore their own thoughts and emotions in their work.
Additionally, the poem also reflects the focus on the individual's inner experience, it presents the idea of death as a personal experience, which is not something that should be feared or loathed but embraced and accept as a natural part of life, and a journey of the individual soul.
Overall, the poem reflects the focus on the individual and subjective experience as a key aspect of Romanticism in its exploration of the speaker's personal emotions and thoughts as she journeys with death.