The Thor actor and his father try to stave off the latter’s symptoms by taking a road trip to old haunts. It becomes a moving treatise on the sadness of letting go of a parentCelebrities are forever taking their parents on televised road trips, and they’re usually cheap, easy commissions. Look how self-deprecating I am, says the famous person as they try to award themselves national treasure status by moving into light-factual programming: the person who knows me best is about to mildly embarrass me on holiday!Be assured that Chris Hemsworth: A Road Trip to Remember is a more serious endeavour. It features some intergenerational joshing as the guy from the Thor movies goes on a motorcycle ride with his old fella, but this is a journey filled with a wistful, desperate longing, towards a destination nobody can quite reach. Craig Hemsworth, 71, has early-stage Alzheimer’s. His mental faculties are starting to slip. But his boy is a Hollywood star, with the resources of a TV company beh...