Historic India, before Partition, is an idea which appeals greatly to me. Not the colonial version, but the idea of an independent and tolerant India of larger scope.
I don’t pretend to have any good arguments for this idea, and I understand (to some degree) how and why it fell apart. I also understand that historic India was itself not very unified. That is in part what makes my attachment irrational, and perhaps the irrationality is part of the attachment itself.
What is your hopeless idea to which you retain an irrational attachment?