Thoughtless'Brilliant' LUCY MANGAN, The Guardian All her life, Susan's loved ones have been hiding a terrible secret from her: If she thinks too hard, her head will explode. Luckily, her devoted boyfriend, anxious parents and fierce best friend are prepared to do whatever it takes to keep Susan safe in ignorant, thoughtless bliss. And until now, Susan has lived happily in a bubble of TV and takeaways, social media and small talk; anything to distract her from