Children’s TV legend Johnny Ball has seldom felt more enthusiastic about life. Aged 87, he celebrated his golden wedding anniversary with his ‘soul mate’ Dianne last year and announced his prostate cancer all clear . Speaking at his south Buckinghamshire home, he says: “I’m laughing more now than at any other time in my life.” With his trademark tongue-in-cheek humour, he adds: “I even bought my wife a bunch of flowers today - the first time I’ve done that in 20 years.” And it’s Johnny’s joie