The guidebook writer and television personality reflects on his cancer diagnosis, social media’s corrosive effect on tourism and the transformative power of travel. Subscribe today at nytimes.com/podcasts or on Apple Podcasts and Spotify. You can also subscribe via your favorite podcast app here https://www.nytimes.com/activate-access/audio?source=podcatcher. For more podcasts and narrated articles, download The New York Times app at nytimes.com/app.