How Obelix Fell into the Magic Potion When He was a Little Boy

Every one of the Asterix stories refers to a decisive moment in Obelix's life: when he, as a six-year-old boy, fell into the Druid's cauldron of magic potion. As a consequence of this accident, he developed phenomenal physical strength. But what actually happened? How did Obelix make that life-altering plunge?
Here is the full story of what took place on that incredible day.