Hop on the bus, Gus

Says Moses: Tharbis resisted and insisted that he remain in Ethiopia as her husband. He then, being "most skilful in astronomy", cast two rings; one which caused the wearer to become forgetful, and the other to cause the wearer to remember all. He gave the first ring to Tharbis, and wore the second himself, and waited for her oblivious nature to lose interest in retaining him as a husband - and when she had forgotten her love for him, he returned to Egypt alone.