If I recall correctly, Akhenaten built a city, Akhatetan, dedicated to the disk god, Aten. The city was fully populated, with people coming virtually worshipping him. He had other gods names stricken from record in some places, but was obviously unable to remove a large selection of them. Outside of his city, he didn't really pay much attention to. His lack of attention was even worse regarding other empires surrounding him. Once he died however, life sort of snapped back to how it was before hand. His city was abandoned, individual gods and goddesses cults were more free to worship again, and international relations improved. Side note: Because his city was built from scratch on empty land, we have an excellent look at how cities in Ancient Egypt were founded and designed. That's hard to see in other cities that were present in their location for centuries. Edit: Also, cults for other gods were forbidden, but it was hard to enforce, as the priest class still had immense power.

Furthermore, why did he change religion? Or can it only be explained through irrational thinking?