I came close to making my first big boo boo today. The assembly is held together with 12 cocktail sticks. Fortunately I was being cautious and paused before the final push together. It was a ratchet type device and I could not see what the point of it was. Eventually I realised I had missed the switch that engages the chosen ratchet.
My other problem was the rubber band. The instructions said use the long one. All the bands I have are equal length. I plumped for the one that was a different colour, although I could detect any other difference.