When I can't explain my reasoning to other person without a feeling of guilt that I am slightly manipulating them.

I am better at noticing when I lie to other people, than when I lie to myself. Maybe it's because I have to fully verbalize my arguments, so it is easier to notice the weak parts that would otherwise be skipped. Maybe it's because when I talk to someone, I model how would they react if they had all the information I have, and this gives me an outside view.