Know any historic reformations?

I can't recall a change of belief by a notable person that was not religious or political. Benedict Arnold changed his political allegiance from the American to the British in the American Revolution.  He kept getting passed over for promotion;  there was backbiting and rivalries.  His story is worth reading.

Saint Paul changed his religious beliefs from persecuting Christians to preaching Christ.  The Emperor Constantine's conversation was another religious one.  King Henry of Navarre converted to Roman Catholicism in order to wear the French crown. He was the next in line by heredity, but the French court was opposed to his Protestantism.  Ghandi left off western clothes as a political statement.

Perhaps the discovery that the planet's revolved around the Sun, not the Earth. Or that patients were more likely to remain alive, and even recover, when doctors washed their hands before examining each of them.

How about one is sports?

Babe Ruth was a pitcher at first, and a good one, but he turned out to be an even better hitter.

Benedict Arnold started off on the Revolutionary side in the 1776 war, but, came over to the British one, where he is seen as a hero.  Americans call him a traitor.  He certainly did change sides.

The head of the Freedom From Religion Foundation, Dan Barker. He was a well known evangelical minister. Now fights to keep the separation of church and state.

Benedict Arnold