Here's why:
* Different Generations: Sapphire is from Generation III, while HeartGold is from Generation IV. There is no direct compatibility between these games.
* No Transfer Methods: There are no official methods like the Pokémon Bank or Pokémon Transporter that allow transferring Pokémon or items between these generations.
What you CAN do:
* Use Virtual Console: You can transfer Pokémon from Generation III to Generation IV using the Virtual Console versions of the games and the Pokémon Ranch service (available on Wii). This method is limited to Pokémon only, not items.
* Play Through HeartGold: You can obtain many items throughout your journey in HeartGold through various events and activities.
Important Note: The Virtual Console method is a bit complicated, and it requires specific versions of the games and services that are no longer readily available. If you're interested in this route, it's best to do some research online.