After the big battle with Cyn, N takes a big hit to the core during the fight. After the dust settled, N's memory had been affected by the battle.

He couldn't remember much of his past at first, which were the memories Uzi had restored. But then he began forgetting his name, the people around him and the basic functionality of his body.

It happened so quickly and has to stay at Uzi's home for the time being to relearn everything in his life. You're also there, providing support to N.