Every hope in this poem is a refusal. "I hope I won't be like everyone else," says the third stanza; the fourth adds "I hope my soul won't feel as cold." The speaker never says what they want to become, only what they are afraid of becoming. That makes the title, "not so high hopes," work in two ways. It sounds modest, as if the speaker asks for very little. But what they are protecting is large: the chance to live a whole life without going numb. The poem sets a childhood imagination with no limits against an adult world that seems to have a low ceiling, and it is a ceiling, literally, that gets the last word.
The four quatrains move through time. The first is memory, the second the present, the third "tomorrow," the fourth old age. The verbs trace the change. The child "run[s] around" and crafts "magic tools made up in my brain." The speaker of the second stanza is "standing here." Running has become standing, and following a paper plane has become being told what to do by "my mother's commands." The paper plane is a good choice of image. It is homemade and fragile, it needs open air, and the child follows it rather than controlling it. Imagination leads and the child chases.
The present is full of tension. "Digging nails in my hands" is a physical picture of clenched fists, anger held in rather than shouted. Judging by the mother's commands, the speaker may still be living at home, though that is an inference from the text. The poem then does something disarming: it mocks itself. "Creating all these silly lines, so called art" undercuts the rebellion just announced. The superiority in the next stanza, where others "have never felt emotions so intense," sits oddly beside that self-mockery. The speaker half believes they are special and half suspects they are just another young person writing a poem. The poem is honest enough to leave both feelings in.
The adult world is described with well-chosen verbs. People are "collecting all the wasted hours on the job that they hate." Collecting is what children do with treasures, such as shells, cards or stones. Here the hoard is wasted time, so even the childlike habit has been turned against itself. In the last stanza the temperature drops. Against the "intense" emotions of the third stanza we get "cold" and "the frost of life without any meaning," and the bones "heavy and old" give the fear a body. Then the poem ends on its most precise image: ambitions "as low as my room's ceiling." A ceiling is a lid, and the measure of failure here is an ordinary domestic object, the speaker's own room, probably the place where the poem was written. The paper plane needed open sky, and the ceiling is exactly what it would hit.
The form is deliberately simple. The poem is in rhyming couplets (AABB), and most of the rhymes are full: day/play, brain/plane, hands/commands, apart/art, hate/fate, old/cold. The long, loose lines have about four beats each, with a bouncy rhythm that sometimes gallops, as in "Sometimes I dream that I am back in the day." The lines have almost no punctuation, so they tumble forward. This nursery-rhyme sound suits the memory of cartoons and games, and it rubs against the bitter content, so the childlike music keeps pulling against the adult worry. Two rhymes are only approximate, else/intense and meaning/ceiling, and both come in the stanzas about the dull adult future. One could read the looser sound as the poem's tidy music wearing thin, and the soft, drooping -ing endings of the last pair do suit a sagging ceiling.
The poem is not significant for grand claims. Its value lies in naming a very common fear plainly: that growing up means slowly trading wonder for routine. It doesn't pretend to have beaten that fear, and it ends on a hope, not a victory. That unfinished quality is what makes it convincing. A speaker who already knew how to escape the ceiling would not need to write "not so high hopes." This one knows it is still a wish, and still has to be earned.