A person sits alone at home and watches time slip by, with nothing much going on in their head except a blank when they try to picture the future. That emptiness doesn't feel peaceful. The speaker says it makes their "body and soul rupture," a strong phrase that suggests real anxiety underneath the stillness.
The second stanza turns that anxiety into a question: what can one person actually do in the world? The speaker offers two possible outcomes. Their life could be a "joyfull spark," something bright that lifts others up, or it could be "useless fools gold," something that looks valuable but turns out to be worthless. The final line asks how they will leave their mark, and it never gets answered.
The mood is restless and uncertain, but not hopeless. The movie reel image makes life feel like it's passing by on a screen, and the closing question shows the speaker still wants to matter, even without knowing how.