By Clare ThorpFeatures correspondentUniversalIn an era where many films and albums are stored in the cloud, "streaming anxiety" is making people buy more DVDs and records – as younger digital generations fear having their life histories erased.Christopher Nolan has achieved some great feats of cinema in his career – but last November he pulled off something impressive on the smaller screen, too. Deep into the streaming era, where physical media can sometimes feel like a distant memory, the Blu-r...