Symbolism, Imagery, Allegory
The poster showed a wide expanse of beach, a sweep of sky with a lone star glittering far away. A man walked on the beach, a small solitary figure in all that immensity. At the bottom of the poster, these words appeared — Do I dare disturb the universe? (19.38, 28.61)
The line is from T.S. Eliot's famous poem "The Love Song of J. Alfred Prufrock," but Jerry doesn't know it. (Psst. You can check out Shmoop's guide to "Prufrock" here.) As with the Mother's Day chocolates there's some dramatic irony going on. Readers can analyze the significance of the poem, and its famous line, in terms of Jerry. But, Jerry can't because he's never read the poem. Still, the fact that he chose this particular poster to adorn his locker does say a lot about him. It tells us Jerry's interested in ideas, he's thinking about taking risks, and questioning established structures and routines.
Prufrock is a thinker, too, but he's fussy, indecisive, and doesn't actually do much. He seems stuck in a routine with which he has a love-hate relationship. He's either an old man being sad about the past, or a younger man imaging himself as an elderly man being sad about the past. Or both. (It's confusing.) He's trying to decide if taking risks is worth the pain that might result and/or trying to decide if he should have taken risks in the past. The poem seems to argue that we should act now, before we end up whiny, aging, and confused like Prufrock.
Jerry, on the other hand doesn't just think about taking risks, he actually takes them. Even though he "[hates] confrontations" (3.20) and is somewhat afraid of the world, he puts himself out there. His decision to refuse the chocolates beyond his 10-day-long Vigils assignment is totally spontaneous. He just does it. Calling Ellen Barrett is more planned out, but there's never any question of him not calling her. He botches the call, and might have done much better if he'd approached her in person, but he's still tries.
In any case, at the end of the novel, Jerry believes that it's better not to take risks. It just isn't worth the pain. It's better to do whatever it takes to keep yourself from getting hurt. Better be a live, boring old Prufrock than a dead or damaged risk taker. Do you think that's the message Robert Cormier is trying to send us, though?