老子 has two distinct uses. First, it refers to Laozi, the ancient philosopher and founder of Daoism (also known as Lao Tzu). Second, it is a colloquial first-person pronoun meaning 'I' or 'me', used by the speaker to assert authority or show arrogance — it carries a rough, self-important tone and is not polite. The second use is common in spoken Chinese but can sound rude or confrontational.