All thoughts are recycled.– Byron Katie
Our stressful thoughts are recycled. They may seem very personal as long as we hold them as true. But they are variations of very old and familiar stressful thoughts for humanity. They are variations on universally stressful thoughts.
Any thought is stressful when it is believed. No thought is absolutely true and life will remind us of that, as will our mind which already knows. Believing a thought creates a position that’s not completely aligned with reality, and that’s inherently stressful.
I should also mention that, in a strict and literal sense, it’s not true that all thoughts are recycled. There are some new thoughts within science, philosophy, and art, although these too are usually variations on familiar themes. From what I know about Byron Katie, this is not what she refers to in her quote.