what tangible item did Tim O'Brien carry in "The Things They Carried"?
I think you have become slightly confused in your analysis of this short story. Tim O'Brien, although he does appear as a character in the other short stories that make up the volume of short stories that bears the name of this story, does not actually appear in "The Things They Carried" as a character. Rather, the narrator is third person and does not appear in the action of the story himself. Thus, as the story opens, it is the external narrator that gives us a list of the various items, both tangible and intangible, that the soldiers "hump" with them as they carry out their orders in Vietnam, but as Tim O'Brien himself is not a character that appears in this story, no items are attributed as belonging to him in the same way that the other characters each are, to a certain extent, defined by the items that they carry.