I confess I never expected to see myself going to the lavatory on prime-time national TV. In fact, the expedition was a failure. Sharing a cell, especially with a young man with a record for GBH, is a very constipating experience. But when I accepted Shine TV’s proposal that I should submit to living alongside a large number of former prisoners, in a real but decommissioned jail, I had agreed to almost anything that might happen.