Probably PEBKAC, as you expect someone to be 100% right. That's clearly impossible, thus it's a problem with you, not them. I expect people (including myself)

Probably PEBKAC, as you expect someone to be 100% right. That's clearly impossible, thus it's a problem with you, not them. I expect people (including myself) to be ~50% right in disputes, based on symmetry.