Question the Status Quo, Cross Domains
Noticing ideas means noticing things that are broken but that everyone, including you, has learned to tolerate. Why is your inbox overflowing? Is email even the right tool? The status quo hides problems by making them feel normal.
Domain crossing is a shortcut to fresh eyes. A programmer who wanders into genetics, logistics, or law doesn't know what the status quo is, so they can't take it for granted. They see software-shaped holes the insiders stopped noticing years ago.
This is PG's advice to students, too: college is your best chance to ratchet yourself into the future. Skip the entrepreneurship class. Take genetics, or spend a summer inside a biotech lab. Ideas come from domain collisions, not from courses about ideas.
Key idea
Broken things feel normal to insiders. Cross into unfamiliar domains, question defaults everyone tolerates, and the tolerated problems become visible.