When Samuel discovered his shadow in Granny's garden last week, he was agog. Once he'd clocked it, he did a proper double take. He raised his hands in the air. So did his shadow. He put them down by his sides again. His shadow did too. Then he started to walk backwards very slowly and burst out laughing when he realised that no matter how sneakily he tried to move away from it, he was stuck with his shadow for good.