The title gives away the setup: this is someone who journeys by reading or imagining, not by going anywhere. The opening lines feel half-lost. "West of elsewhere" is a place that can't be found on a map, and "slept in my clothes" suggests a person too tired or too unsettled to bother undressing, as if they've drifted through the day without really arriving anywhere.
The middle lines turn the trip into something both safe and risky. It's "a journey on paper," so nothing physically happens, yet the speaker still travels "along harm's way," a phrase that hints at danger, or at a pull toward trouble, even from the comfort of a chair. The ending is quietly funny and a little sad. The speaker pretends to have difficulties and hurries off to bed, as though the adventure has to be cut short or an excuse is needed to escape it.
The mood is drowsy, wry, and slightly evasive. The poem seems to be about the gap between imagining a bold life and actually living one.