Basically this is Descartes fault. In the thing we were discussing Descartes uses geometric proof as an example of the Clearness and Distinctness Principle which is one of those stupid ideas that Descartes uses to justify fairly terrible arguments for the existence of God.
I said that it was interesting that the geometric proof he uses, relied on an axiom called Euclid’s Parallel Postulate which is famously worth avoiding and only holds in certain circumstances. I suggested that this exposed weakness in the veracity of all his initial assumptions.
About the time I got this far, the life had drained from the faces of everyone in the class and now I think everyone hates me.