Outside of Japan a child learns to cycle when they're ready. In Japan a child learns to cycle once they're too heavy to ride in a child seat on the back of mum's bicycle.
Its a natural progression, you crawl, you walk, you get carted around on mum's bicycle until you're too big then you're pushed out of the nest and find yourself on a bicycle wobbling from side to side trailing a parent to the dry cleaners.
By the time you're old enough to question it bicycling has become second nature.
