Familiarity between living things determines how we connect. The wundt curve is a bell-shaped curve relating pleasantness of activity to intensity of the stimulus. For example, someone you don't know can't tickle you, or you can't tickle yourself. The element of surprise, a pleasant level of familiarity helps turning itching to tickling. scratch-off moves in an eerie way between itching and tickling asking how we will balance this with technology as it evolves inspired and derived from ourselves, hoping for a ticklish sensation to scraping walls.