This Term, the Supreme Court was presented with a prime opportunity to provide some much-needed clarification on a "backdrop" issue of law-one of many topics that arises in a variety of legal contexts, but is rarely analyzed on its own terms. In J.D.B. v. North Carolina, the Court considered whether age was a relevant factor in determining if a suspect is "in custody" for Miranda purposes, and thus must have her rights read to her before being questioned by the police. Miranda, like dozens of other areas of law, employs a reasonable person test on the custodial question: it asks whether a reasonable person would, given the circumstances, believe that she is free to leave. The issue posed by J.D.B., then, was whether age counts as part of a suspect's "circumstances" for Miranda purposes. Unfortunately, the Court's June opinion managed only to compound the confusion and, in an ironic twist, did so while extolling the virtue of providing "clear guidance to the police." This Essay critically examines the J.D.B. opinion, using it as a lens to both critique the traditional objective/subjective distinction and articulate a more honest interpretation of the reasonable person test-one based on the uncomfortable truth that the test is, at its core, arbitrary.