Friendship
I believe in friendship, but there’s something dreadful about being friends with someone who’s not friends with you. Sharing things they wouldn’t share with you; giving them preferential treatment they won’t give to you; caring for them in ways they wouldn’t reciprocate; inviting them for intimate events that they wouldn’t invite you for.
And it’s even more painful when this realization hits you years after being delusional that a friendship existed.