I’ve been to a num­ber of Wire­less and assort­ed day fes­ti­vals in Hyde Park but gen­er­al­ly not been won over. Pre­fer to wan­der around the are­na know­ing my tent, a cup of tea and a snooze on a musty sleep­ing bag are only a stroll away. But Field Day in east Lon­don’s Vic­to­ria Park was…