The poem begins gently. The speaker finds a garden in their mind, a pleasant place with "good company," and stays there. The word "escapist" in the title tells us this is a retreat from something, though the poem never says what. Judging by the tone, it could be loneliness, boredom, or simply the ordinary pressure of being in the world.
Then the poem turns sharply. The speaker stays "till I was ill and vomited," and the next morning there is cold and "pain in pissing." The language is blunt and physical, and it clashes with the dreamy garden of the opening. The body has its say, and it isn't kind.
The mood shifts from peaceful to uncomfortable, even darkly funny. The poem seems to suggest that escaping into the mind has a cost, and that the real body and its needs can't be ignored for long. The flat, matter-of-fact ending makes the point without any lecture.