"Fwather"
(I will omit the goblin's voice for word clarity)
"Yes, son?"
"Why is skin white?" Uri asked his tall green goblin father. He kind of had an inkling as to why he has a different skin color compared to both of his parents in this isekai world.
'It's because I'm a human in my last life!'
(It's not, you're a child outside)
"Hmmm. You're just malnourished! I took part in the war with the giant chickens while your mother was pregnant for 10 months and could not watch her food intake."
(No, goblins don't carry their child for 10 months, only 9 months. And, it's not only food intake that he forgot to watch out for his wife.)
"Ohhh. I guess so!"
"But it's fine. You'll be strong! Regardless of color! As! I! Am! The! Father!"
(You are not the father!)
"Yep! I will try my best too!"
And so, the real training arc began with Uri at the age of 2.
He followed his father's morning routine, albeit with 0.0001 of intensity. For every 10 meters he walked, his fatherhad already lapped 10 times around their house. For every 1 pull-up he made, his father was already on the next exercise watching him with a wide grin in his face.
'This kid! My kid! A fearsome fellow! So hardworking at young!"
And so, this goes on and on for 10 years.
Uri learned the way of speaking of the goblins, customs, and history. He also committed to his memory the map at least in the nearby regions, as that is what's just available.
He also joined his father in his morning routine while being taught goblin's martial arts. What he found amusing is that compared to what he learnt as a soldier, this martial arts is more barbaric, but oddly enough, it has a system to it which is only possible due to the goblin's body structure and can easily catch one off guard.
And, he really tried hard looking for it.
But there's just one book. In that big ass library. Magic.