It's so that he can remember why he killed the goddess that summoned him and why he's cursed with the time-loop
I thought they already said he did that because Tia had to die/he wanted to bring her back
We don't know the reason he killed the goddess in the first memory for now. And there's something kinda fishy going on as well because the goddess that summoned him is the goddess of love, but he's been cursed with a time-loop even though no god (as far as we know) has the ability to control time. I recall he did mention he went a bit crazy after seeing Tia die so many times, and he tried to revive her, the price being killing everyone in order to keep her alive. And he did mention he tried to kill the goddess to get out of the time-loop as well. However those things happened AFTER the first memory, so after he had been cursed.
Hey yeah! You're making a lot of sense, I've been forgetting too much about this manga lmao, thank you
Np! It was easy cuz I binge read it yesterday
His first memory best be in the next chapter I stg, we've been waiting too long to find out. Though that being said, we've been waiting so long that I no longer remember why it's important that he gets his first memory back. Excited either way