Watch the first episode of the Garlic Jr. Saga. Garlic says that he's been in the dead zone for ten years. But when he was sucked in there, Gohan was alive and he caused him to go in the dead zone. How could Gohan be alive then? If you've seen the Android/Cell saga, you know that they spent 3 years training before the androids showed up. After three years, Gohan was 10. Then he went into the time chamber, and he was 11. That means before the 3 years, he was only about 7. That means he must have been 7 or younger during the Garlic
Jr. saga. And Garlic said he'd been in the dead zone for 10 years. If that was so, then at that time Gohan would have been negative 3 years old!