The copywriting is incompetent, so let's just make do with it. In this era, time travel in the novel? Normal! Wearing books? Normal! Is there a system? Very normal! Doing tasks? More normal! He has accepted these bizarre things. Can't he be allowed to carry out the mission with realistic memories? Even if God tests him and forces him to lose his memory, why not give him a normal system? What the hell is it about assigning him a system that also has amnesia and always encourages him to save the world? Are you sure you're not trying to kill him?