El dolor es inevitable. El sufrimiento es opcional.

We went straight to Murakami's own running memoir, *What I Talk About When I Talk About Running*, and found the exact line — "Pain is inevitable. Suffering is optional." — present in the text, where he offers it as a mantra he repeats to himself while running. No stronger named originator with a documented earlier instance surfaced (Buddhist and Stoic parallels are thematic, not citable predating sources for this exact English phrasing), so nothing pushes this toward disputed or misattributed. On the strength of its documented appearance in his published memoir, this quote is verified.