: The phrase acts as a pun on the geological formation of diamonds, which are created when pure carbon is subjected to extreme heat and pressure deep within the Earth's mantle. Without this pressure, the carbon might only become graphite or coal.

: Carlyle often focused on the idea of the "hero" in history, believing that great individuals are shaped by their struggles and efforts.

Robert Griffin III's 'No pressure, no diamonds' line explained

: The phrase gained significant modern popularity through athletes like Robert Griffin III , who used it as a personal mantra to describe the necessity of performing under the spotlight. 2. Psychological Deep Dive: Grit and Resilience