If you don’t have kids you probably think going to the supermarket is a necessary but pretty boring job on your to do list. You don’t know how lucky you are. Enjoy it, the peaceful browsing of the aisles where your biggest problem is the old lady who takes too long to choose what yoghurt she wants. Once you’ve had kids, the supermarket trip becomes the stuff of nightmares. If you have a newborn you’re still generally in the lucky group as they tend to sleep most of the way round, but once they hit the toddler stage, you need…