The relative wetting of polymer surface was understood via molecular-level structural analysis. The disparity in water dynamics between PTFE, PE, and PVC versus that in PMMA, N66, and PVA is largely attributed to the capacity for and extent of hydrogen bonding in the latter group. Wettability increases in the same order as increasing polymerwater hydrogen bonding: PMMA > N66 > PVA. For the non-hydrogen-bonding polymers, affinity for water was inferred from orientational preferences of interfacial water molecules induced by the polymer-water interface. For example, water molecules, on average, tilt oxygen towards the PVC surface based on strong interactions with the chlorine atom. By contrast, fluorine in PTFE is more weakly interacting and does not perturb water structure, implying lesser affinity and greater hydrophobicity, and PE illustrates a trend wholly opposite from PVC. Thus, we show how distinct molecular physics can give rise to similar macroscopic observations or measures of hydrophobicity, which may provide future rationale for materials selection or explaining other phenomena. Analysis also highlighted and explained differences in surface hydrophobicity that might arise due to crystallinity or chain tacticity.