Amphiphilic diblock copolymers are robust building blocks for constructing functional supramolecular structures such as worm-like and spherical micelles and bilayers (polymersomes). One of the advantages of using polymeric blocks is that their chemical nature can be used to control attributes such as the flexibility of the structures formed. Herein, we report on the flexibility of worm-like micelles prepared from polyethyleneoxide-b-polystyrene (PEO-b-PS) diblock copolymers in which polystyrene forms the hydrophobic core and polyethyleneoxide forms the hydrophilic shell. In its melt state polystyrene is a glassy polymer (tg = 100oC) and we find that this glassiness is preserved even when confined to the nanoscale dimension of the worm micelle core. Estimation of the apparent persistence length of worm micelles formed from two PEO-b-PS diblock copolymers that differ in their molecular weights indicates that it is far less flexible than previously characterized worm micelles with fluid cores. The glassiness of the core is also evident by lack of fluorescence recovery after photo bleaching. Interestingly, the rigidity of the worm micelle is interspersed with flexible ‘hinges' due to defects, the periodicity of which is dependent on the molecular weight of polystyrene block. In addition, the hinge flexibility exhibits temperature dependence up to 80oC which is indicative of increased thermal motion around the hinges rather than any obvious melting of polystyrene. Addition of block specific solvents such as xylene or chloroform homogeneously fluidizes the hydrophobic core and imparts flexibility to the worm-like micelle along its contour. This allows for ‘molding' the worm micelles in flow and thus enabling the creation of high aspect ratio nanoscale rod-like structures with tunable flexibility.