Zen Buddhism In One Phrase

A Zen Koan.

A Zen master was traveling through America. He took part in an interview for a podcast when the curious interviewer asked him a peculiar question:

"I've been listening to your lectures for years, but I just don't understand. Could you put Zen Buddhism in a nutshell? Can you reduce it to a simple phrase so that I might understand?"

The zen master let out a deep laugh.

"Everything changes"