It really was too much to ask my 81 year-old mother to walk all the way from London to Edinburgh, so I suggested that we cut a few miles off the route by taking the train to Oxford.

In the fine university city we admired the old colleges and stopped in the doorway of a tea room to speak to the proprietor. She offered us a table at the back, but we explained that we couldn’t linger.

As we hunted down the blue cycle path signs that would point us north again, my mother confessed that she really couldn’t face any more walking. She confirmed that she still had her senior railcard in her handbag and I agreed to her plan to catch another train for the rest of the journey home. Even if it cost a fortune and we had a long wait for the next train, this would be preferable to a long, slow trudge back to Scotland with an unwilling geriatric.