It's true when you think about it, but back when I read it the deeper level adult stuff just wooshed over my head.
Here's one, you know how Sha Wujing has a necklace made out of nine humans skulls?
The kid me would be like woah okay, so he's a man eating badass, that's cool I suppose I'm sure those a dime a dozen on this trip.
Where as you grow up later and it suddenly hits you: wait a second, this guy controls a river that you have to cross if you want to go to the west, and those nine skills are monks that wanted to travel to the west before (that's why they don't sink in the river like normal human heads, and why he collects them), and Sanzang just happens to be the 10th incarnation of the Golden Cicada, who put him up to this? Why was he demoted from the Celestial Court again? What he smashed a lamp? Hm...
Even in this game where Wukong was fighting Yang Jian at the start and he was calling Yang Jian his young nephew and a dog for the celestial court. That's actually a much more personal insult to Yang Jian than just Wukong having a go at him because he owns a dog. Yang Jian once lead his own rebellion against the Celestial Court and Jade Emperor to free his mother, until the Jade Emperor smoothed things over and "hired" Yang Jian and his army as his PMC. Wukong was saying look at you, your uncle now lords over you and treat you like his attack dog. Look at me I'm 齐天大圣, equal to the Jade Emperor and I do whatever I want, nephew.
See they don't even show that in the 1986 TV show, in the show Sha Wujing's image is sanitized