Henry Dobbins is described as a good man and great soldier—he's like America: big, strong, good intentions. He wasn't fast, had fat jiggling at his belly, and he wasn't that sophisticated, but he was reliable and "drawn to sentimentality." O'Brien remembers how Dobbins used to keep his girlfriend's pantyhose wrapped around his neck before they went out on an ambush. He said they were his good luck charm. He would breathe in her scent, and said he liked the memories they brought back. Sometimes he slept with the stockings against his face. Mostly, though, the stockings were of superstitious value. Dobbins believed they kept him safe from harm. O'Brien said many men in Vietnam felt a superstitious pull, and Dobbins was one of them: he believed the stockings had protective power, like body armor. He was ritualistic about the way he put them on before an ambush.
Henry Dobbins is not described as the most athletic or smart guy; he's not the one you would expect to come out of war without any injuries. O'Brien spends ample time describing how he remembers Dobbins as a simple, jovial man. The stockings were Dobbins' good luck charm to protect him from harm or death, and he wore them without fail. O'Brien notes that mostly everyone felt mildly superstitious in Vietnam, clinging to arbitrary things to protect them against something as arbitrary as death. For Dobbins, it was his girlfriend's stockings.
Some people joked about it, but everyone "came to appreciate the mystery of it all." Dobbins never got hurt, not even a scratch. In August, he tripped the wire of a Bouncing Betty, which didn't detonate. A week later he was out in the open of a firefight; he slipped the pantyhose over his nose and came out fine. Everyone in the platoon began to believe in the pantyhose: his survival was a fact, so their power was fact.
The stockings became a mystery and point of fascination because they did, in fact, seem to be Dobbins' body armor. When the platoon began to believe in the pantyhose it was because fact had become what existed before them: the pantyhose worked. Facts, then, were arbitrary too because they were dependent on chance.
At the end of October, Dobbins' girlfriend broke up with him. He was quiet for a long time while he stared down at the letter. After a while Dobbins took out the stockings and wrapped them around his neck claiming they would still work: "The magic doesn't go away."
Even after Dobbins' girlfriend breaks up with him, he doesn't let this take away from the stockings' power. This superstition is what he needs to carry him through and make him feel safe against the constant threat of death.