Complex sentence: As a young boy, Harding became fascinated with the Stone Age period, and it was then he learned flint-knapping from his Uncle Fred, and within only a few months became a skilled knapper, crafting many different hunting tools from pieces of flint.
Split into simpler sentences: As a young boy, Harding became fascinated with the Stone Age. He learned flint-knapping from his Uncle Fred, and in only a few months became a skilled knapper, crafting many different hunting tools from pieces of flint.