A self-learning lock cylinder assembly or lock tumbler and tools capable of teaching the self-learning key configuration of a pre-existing key is disclosed. The individual performing the self-learning does not need to have prior locksmith experience. The individual performing the self-learning procedure can verify that the original key and copies of the original key function properly within the lock cylinder prior to final assembly and installation in the lock through a self-learning test housing. The pre-installation testing eliminates problems associated with an incorrectly assembled lock cylinder.