A roller bearing includes inner and outer rings each having a raceway, an annular space between the raceways, and a plurality of rolling elements and a lubricating grease in the annular space. The raceways have a predetermined roughness value within a first predetermined range, and the lubricating grease contains graphene particles uniformly dispersed in a suspension in the lubricating grease. The graphene particles have an at least substantially circular shape, a diameter within a second predetermined range and a thickness within a third predetermined range. An amount of the lubricating grease in the annular space and the first, second and third predetermined ranges are selected such that a self-regenerating mat of graphene that at least partially coats the raceways will develop in use as a result of a relative rotation between the inner and outer rings and the rolling/sliding of the rolling elements on the raceways.