I understand the utility of lying to other people, but why do they lie to themselves?
Most Helpful Guy
This could be for a number of reasons but all on the same boat. They refuse to accept reality for what it is and lying to themselves is them making excuses for something, ultimately laying out possibilities in their head as to why it is the way it is only because they do not want to accept what may be the case, to be the truth they'd rather make up another possibility as to why it is because that's a reality that they'd be more comfortable letting in.1
Most Helpful Girl
Because taking blame and facing our own flaws is hard for people. The other answer is they are sociopaths that see what they say as truth even when presented with concrete proof what they are saying is a lie.1