self-delusion

plural self-delusions

1. countableuncountableThe act of deluding oneself, or the state of being so deluded.

   This self-delusion is even more the case with Trotsky, whose bloodstained intolerance is generally passed over because the 1960s student generation pretended then, and pretends still, that Trotsky was in some way a freedom-loving, Gulag-free alternative to Stalin.

   2010, Peter Hitchens, The Cameron Delusion, Bloomsbury Publishing, →ISBN

   Synonyms: self-deception