C7 bulbs or C9s? How Christmas lights became a nerdy obsession

Adorning trees with electric lights has been common since the early 1900s. Whether you love them – or love complaining about your neighbours’ – this year their ubiquity and inventiveness has become undeniable

I love Christmas lights. I am writing this in my living room, with no overhead lights on. All the illumination is coming from seven strands of lights – one on the tree, six more around the walls; several hundred bulbs. I love them so much that the ones that aren’t on the tree stay up all year. Every year I buy a few more sets, for no good reason – I just find it hard to walk past a shelf of lights without buying a set. I’m not alone in my passion. Although John Lewis won’t give out exact figu...