Tino SehgalÕs ÔThese AssociationsÕ was shortlisted for the Turner Prize. A Turbine hall full of movement, stillness, visitors enchanted by tales of lost loves, leaving home, writing books. Associates rejoin a now chanting throng. Confusing? Beautiful? Art? Far more. Maggie Smith, at 81 the oldest Associate, reflects on 2012's magical summer.