In a 'Goku never hit his head' fanfiction, Goku's power level progression would likely be different in several ways. For one, he may not have the same connection to the Spirit Bomb. The Spirit Bomb was a technique that was somewhat related to Goku's kind - hearted nature which was influenced by his head injury. Without that, his power might be more centered around his Saiyan genetics. Also, his ability to go Super Saiyan could be affected. The emotional triggers for going Super Saiyan in the original story were related to events that happened after his head injury. Without that injury, the path to achieving Super Saiyan and subsequent forms could be very different, perhaps more in line with traditional Saiyan rage - based power - ups.
Well, Goku's power level progression could be different in that he might be more in control of it. Since the head injury had some impact on his psyche, without it, he could have a more calculated approach to increasing his power. He might not rely as much on the Kaioken technique, which was developed in part due to his need to overcome limitations caused by his injury - affected development. Instead, he could focus more on pure Saiyan power - up methods like the Great Ape transformation and evolving it further.
If Goku never hit his head, he might not have become the kind-hearted hero we know. Maybe he would have remained a fierce warrior focused only on power and conquest.
One possible plot could be that Goku's power development takes a completely different path. Without the head injury that altered his original Saiyan nature in the official story, he might be more in tune with his Saiyan instincts from the start. This could lead to him being more aggressive in his battles and perhaps having a different moral code when it comes to fighting. He may not have the same innocent and somewhat naive view of the world that he had in the original story, which was partly shaped by his head injury.
If Goku never hit his head, he might have remained the evil Saiyan he was originally intended to be. This would completely change the entire dynamic of the story and the relationships between characters.
His life might be more focused on his training and adventures. Without the family responsibilities of being a husband and father, he could freely travel the universe seeking stronger opponents and new challenges. He might also be more involved in protecting the entire universe rather than just his family.
Goku's power is measured in different forms and levels in his universe. When it comes to Legendary Pokemon, some of them have the ability to control elements like time and space. In a fanfic, Goku in his Super Saiyan Blue form might be able to match the power of a Legendary Pokemon like Palkia, which has power over space. But it also depends on the situation. If Goku is in an environment where his Ki attacks are less effective, like in a dimension where psychic powers are dominant, he might have a harder time against a Legendary Pokemon like Lugia. Overall, it's a complex comparison as their powers are quite different in nature.
In the context of this fanfiction, his high - born power level would have a huge impact on his early days. He may grow up faster in terms of physical strength and combat skills. Since he's born with such power, he might not face the same challenges as other Saiyans in developing basic abilities. However, this could also lead to overconfidence. And perhaps he has to deal with the burden of high expectations from his community at a very young age. He might be constantly pushed to test his limits, which could be both a good and a bad thing for his development.
Goku could show his intelligence by teaching others. For instance, he could pass on his combat knowledge to his friends or even to new generations of fighters. By being able to break down complex fighting moves and strategies into understandable parts for others, it shows his deep understanding of martial arts, which is a form of intelligence.
Well, if Goku didn't lose his memory, his relationships with his friends and family could have developed differently. Maybe he'd have fewer conflicts or approach problems with a clearer mind.
The power dynamics would also change in terms of how Goku's friends interact with him. They would be very cautious as they try to figure out if it's really Goku or Baby in control. Goku's power, which was once a source of hope and protection, could now be a threat if Baby is in charge. And if Goku is fighting against Baby's control, his power might be inconsistent or erratic as the two forces struggle within him.
Goku in the manga doesn't hit a power level of 8000. The power escalation in the story doesn't go that high for him. There are various factors and story arcs that determine his power growth, but 8000 isn't one of them.