The Ten Fetters: #8, Conceit
You probably think this post is about you, don't you?
Conceit (māna) is pride, self-centeredness, and most deeply the felt sense "I am." There's the three comparative conceits: better than, less than, and equal to. All of these are delusion.
Deeper than these is the lingering sense—even though personality view (sakkāyadiṭṭhi) has been uprooted with stream-entry—that the self is a persistent object. This sense, and the comparison with others that it manifests as, is a large part of what fuels rebirth, as well as Othering, and all the fear and violence that comes with it.