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Song Prompt: Kings and Queens ~ 30 Seconds To Mars
Sometimes You Forget.
If there was anything Goku truly believed in, firmly, it was complete and constant equality among all persons. He believed that everyone deserved a second chance, and sometimes a third, and he didn't believe anyone had the right to take a life, or ruin one, and the only reason he'd ever kill anyone himself was to protect his loved ones. He didn't believe it right to have a favorite family member, or a favorite pet, or a favorite friend.
Now, that wasn't to say he wasn't closer to some friends than he was to others; it was simply a fact that Goku liked everybody. He didn't have much reason not to, the way he saw it. A friend was a friend, and he'd sacrifice his life for them, if he had to, regardless of closeness. If they asked, he'd come to visit them (although, Goku wasn't much for visiting, but he'd do it) and if they needed help, he'd help them.
So, with this equalizing belief, there was no reason for Goku to treat Vegeta any differently than he would anybody else. He knew, of course, that there were certain things that Vegeta disliked, and so he couldn't really do them in his presence; Vegeta, for instance, very much disliked sitting on the sidelines, and so any time Goku was over to Capsule Corp, the shorter Saiyan would demand that he spar with him, whereas Piccolo or Tien would spar with anybody, and were content to watch. Also, Vegeta found it terribly irritating if he was interrupted, and although such a thing would be irritating to anybody, it was one of Vegeta's pet peeves, whereas someone like Tien or Krillin wouldn't find it to be such a big deal.
But still, even though Goku was observant enough to notice the little quirks and habits of his friends (Krillin, for example, had a habit of going after women Roshi would like, which hadn't proved effective in the slightest), he still didn't find either of them any more special than the other. Krillin was Krillin, Piccolo was Piccolo, and Vegeta was Vegeta.
At least, that's how it seemed, for a while.
One of Vegeta's most prominent traits was his pride, obviously. Goku had discovered that the first time they met. Vegeta was the type to love announcing himself on the battle field; he appreciated the fact that those who died by his hand knew who had killed. A Saiyan thing, Goku had decided, but a Vegeta thing especially. He was a very self-flattering man, proud of who he was, although not always who he had been. He was not hesitant to remind people of this, either, nor was he embarrassed to remind others of their place.
This was true especially in relation to Goku, whom Vegeta repeatedly called "Third class", among other not-so-nice things. Vegeta had nicknames for everybody, really. He, for instance, insisted on calling Bulma 'Woman', Trunks 'brat', Krillin 'baldy'…18 forever remained 'the toaster', Piccolo 'Namek', and of course, Goku was either 'Kakarotto' or 'Third Class.' The two names were used about equally, and innumerably.
Point being, Vegeta liked to consider himself above everyone else. This trait seemed to lessen over the years, although his pride and ego were as large and inflated as ever. But, as Goku tended to like equality, he never thought of Vegeta as anything particularly high and mighty, although he did make a fantastic sparring partner.
But sometimes, things about him would strike Goku, and startle him a little bit. For example, once, after sparring, the two had been drinking water, and dumping on themselves, in order to cool down. Goku made a remark about how hot it was that day, perhaps the warmest that summer, to which Vegeta replied, "Hardly. This would be an average day, on Vegeta-sei. But then, my room overlooked the ocean."
And then Goku remembered that once, Vegeta had lived in a palace. Vegeta had been a child who was growing up to be a king.
He had noticed it before; sometimes, he would see it in the regal way Vegeta walked, and the way he squared his shoulders. He noticed it in how, despite how much he might try, he could never eat as neatly as the elder Saiyan could, regardless of speed. He would see it in the calculating, disdainful look Vegeta often shot at people or things he found ridiculous.
It wasn't something that stuck Goku often, but when it did, it struck with powerful clarity. Sometimes, it gave him this small sense of awe, like, I know a famous person.
But then, almost right after, he'd snap out of it, because really, it was only Vegeta.
I think Goku sometimes forgets that Vegeta really is a prince, and not just one of his good friends. I also think he tries to ignore that fact, but whether he does this to make himself believe that he's the most special one, or to stop things from being complicated is beyond me.