EXACTLY!
Pre-op pain is bad, crippling, horrible, demoralising, and only gets worse. Post-op pain can be as bad, sometimes in the first days.
But the key fact is that the pain gets BETTER.
One's condition post-op is sometimes worse than pre-op for a few days or up to a MONTH later. One has to learn to roll with the punches, to relax, take medication, let the body do its thing and heal. It will do this all on its own. PT can be helpful with this process, but the key element is time.
But it will happen. Millions of TKRs are done every year; this wouldn't be so if it didn't work.