I've purposely set the curve of tests to be unfairly high
Why do you feel the need to be unfair to your students?
To teach those students a lesson. They have been too arrogant about their abilities to learn
I think that you should set the curve somewhere a little more reasonable. I get wanting your students to aim high, but you should still make it something attainable.
Why would I do that? It's good that they have a little more work to do.
It might be just unattainable for some of your students though. Setting the curve at an average might be a little more beneficial for your students.