This paper argues that natural selection strongly favors atemporal memory storage—architecture where temporal ordering emerges through retrieval operations rather than being intrinsic to stored states. Three convergent selection pressures drive this outcome: (1) Resource pressure: Temporal indexing as structure imposes metabolic costs that temporal information as content avoids. (2) Speed pressure: Associative retrieval enables faster adaptive response than temporal lookup under time constraints. (3) Flexibility pressure: Atemporal storage permits adaptive recombination that temporal binding constrains. The paper formalizes these pressures through a minimal competing-architectures model, showing that as system complexity increases, the fitness advantage of atemporal architecture grows without bound (resource costs scale as O(n), speed costs as O(log n)), while the advantage of temporal accuracy is bounded. This yields a complexity threshold beyond which atemporal architecture dominates. Calibrated claim: We demonstrate that atemporal storage has strong, compounding selective advantages making it the expected evolutionary outcome for complex systems. We do not claim logical necessity; temporal architectures remain possible but face cumulative selective disadvantage. Where precise temporal encoding exists (time cells, interval timing), it requires specialized mechanisms—consistent with a default architecture lacking intrinsic temporal structure. The paper engages directly with temporal coding literature (time cells, Temporal Context Model, phase coding), showing these are either specialized additions to default atemporal architecture or temporal-as-content implementations consistent with the thesis.