An
intentionally flawed square on a
quilt.
Humility squares are alleged to have originated with the Puritan quilters, since the creation of a flawless, perfect quilt would be an affront to God, for only He could make perfect things. So each quilt would have one square which would intentionally contain errors; this would teach the quilter humility.
Of course, the assumption that the quilter needed to intentionally err to be imperfect wasn't prideful at all....