  One should distinguish knowing a self-evident proposition from knowing that that proposition is self-evident. The former does not imply the latter. Someone might know some self-evident proposition, such as that if A is better than B and B is better than C then A is better than C, but lack the concept of self-evidence, so couldn’t know that that proposition is self-evident. One might even know a self-evident proposition whilst endorsing a theory according to which no propositions are self-evident.