One of the central points of the modernization of liability law was the redesign of the statute of limitations. The previous system had proven to be too complex due to an overwhelming number of limitation periods. The reform led to a significant reduction in the number of periods and a considerably broader scope of the standard limitation period. The necessary trade-off for this simplification is the introduction of a subjective starting point for the statute of limitations. The commencement of the limitation period now depends on whether the creditor is aware of the facts that establish the claim or should have been aware of them without gross negligence. The work examines the practically significant question of under what conditions knowledge or grossly negligent ignorance can be affirmed.