I learned bobble stitch when I was of primary school age. One of my aunties taught me when she had come to visit on holidays. You can knit bobbles in just for effect or you can make patterns with them to create a three dimensional look to your knitting. I love the effect in the video with the medley wool. The bobbles lift it into a class act. They are not hard and a bit of practice will make you able to knit bobbles very quickly.