Silent Struggle

"HAAA… HEEE… HAAA…" Every few inches he crawled forward with the help of his right hand it appeared like it took an effort as if he was struggling in a battle that will decide his life or death 

And after every push, he takes a short rest, then shouts, " F*ck you, All-seeing piece of shit." Then the crawl continues

How did he not tell him such a thing? What is difficult about *Be careful, you will face gravity tens of times greater than what you are used to*?

 Is it possible that he forgot that the gravity of this planet is greater than that of Robin in this frightening way? 

Or did he not look into it as he did not care about it? 

Or did he know but thought it was a silly thing to talk about?!

What would have happened if Robin acknowledged his mission as soon as he told him and came here when he was still at level 11? Would he have died as soon as he arrived..?!