Are the only knowledge we have about pleasure and pain?

The most sublime blissful state of perception of beauty. The most agonizing state of perception of horror. The worlds between them are the only true knowledge we have. We pursue the first one and run away from the second one in all the possible ways that maybe we cannot conceive. They are our universal orientation and somehow the basic principles of 'reality' itself. Existence shows tendency of equilibrium, harmony, symmetry and order that manifests a sense towards a determinate 'desirable' state. What desires such order and perfection over any other state and why, perhaps we are not ready to know.