@Lucca_R
Bro, imagine a guy teleports you on top of a huge skyscraper and then they go :
"So now, you're immortal. Go jump from this tower. I don't know if you're scared of heights or anything and you'll probably feel pain but just do it."
Even if you're immortal now, you don't know if you also never feel pain. And even more, your mind is still that of a human. So for a guy living in his own little bubble like MC, it must have been quite the horrible ONE THOUSANDS YEARS.