This reminds me of this story of a man who played mental chess in a soviet gulag to stay sane. https://www.bbc.co.uk/news/magazine-25560162 https://www.bbc.co.

This reminds me of this story of a man who played mental chess in a soviet gulag to stay sane. https://www.bbc.co.uk/news/magazine-25560162 https://www.bbc.co.uk/news/magazine-25560162