Just bought a new toothbrush – ‘SOFT’ and price and green colour dictated the choice. On first use I discovered it to have a quirkily-shaped handle with ridges and knobs. My hand immediately adapted to the suggested grip – I assume those knobs and ridges are guiding the fingers and thumb. And then I was amazed to discover that somehow I brush in a pattern due to the hand stance, so to speak. I was and am truly impressed. And would likely chuckle heartily to find out the ridges etc. are purely decorative, and that the configuration of the handle is accidental.