yea and I was thinking the same thing. That tends to be the problem with adding chars in the future who existed in the past. But honestly for vegeta, since he was a kid, they could just say it was a repressed memory.
I'm really hoping they explain this a bit because if they don't then what was the point of that whole scene?
I'm also guessing vegeta didn't see Beerus as a mortal. He's literally an immortal God. Zarbone and them where all mortals so vegeta had some measure of reference, but how do you measure the power of a God?
This goes along with my theory of the essence of "God Mode". God's fight on a different wavelength than mortals. No matter how high Goku's power level was he wouldnt be able to harm Beerus without the God Essence.
Which makes me think Vegeta might have a bit of the God Essence in him already from how he was able to land a finger on Beerus. He may be related to the original SSJ God which which has something to with the royal saiyan bloodline.
Then you might think "well why did goku need to go God mode to fight freeza?"
I don't think what we see right now is the true God Form. And I don't think freeza gained his new form and power on his own. I think he got help, with or without his own knowledge. I think Golden Freeza is a form just like SSJ God or they originate from the same category.
I just think vegeta has closer rides to the ssj God than goku which will play out later on in the story.