Left is just really little more talented then right (afterall he did fist sense Qi)
But right is much more intelligence and hard working (He did something with Qi and did control it better after 3 months
It didn’t really make sense that they know the word ,,universe,, but not the word ,,pain,,
Afterall they where just normal human that have a Immortal lifespan so they did feel ,,pain,, before