...went around saying to himself, "Be careful; be careful; don't be deceived." He would then answer himself, "Okay, okay. I'll be careful." This eventually became the basis for a well-known koan:
An old master questioned himself and answered himself; which one was the real master?![](https://lh6.googleusercontent.com/lm2qyT4V6WzEX0DzMfF3QvAngn4fHwAaWpc87tzurGyTnhWCprdsdYpAdo2mttCh_ClpmNHKqWl2xy-sYuBWXnpP7JLd6K98xc1lPZOrviif14WGPyro)
An old master questioned himself and answered himself; which one was the real master?