> You're logging in so they know who you are, but you refuse to keep a cookie in your browser so they won't know who you are? The two sentences are not in cont

> You're logging in so they know who you are, but you refuse to keep a cookie in your browser so they won't know who you are? The two sentences are not in contradiction at all. As long as he has the credential (password and perhaps 2FA), he should be able to log in. The cookie is a convenience, and should not be a requirement.