>>280881371Well, he WAS a hermit in the middle of some hard mode demon forest. Anime doesn't say how long he was there, but he power leveled enough to curb stomp wyverns and scare the B-rank side character. So even at ultra EXP earning rate of a MC, he's been there a while to go from F to A.
Even as a hermit myself, I found at 3 months of no one around, that shit will seriously start to fuck with you. He's had at least 6 months, probably years. He's definitely attention starved.