"Gonna Change My Way of Thinking" is a feature spotlighting notable examples of retcons that don't fit into the framework of Abandoned an' Forsaked, which is specifically about stories that outright "overturn" older stories. There are many examples of "retroactive continuity" that do not actively abandon the works of the past (especially cases where the overall continuity was rebooted). Some of them are minor, some of them are major. Today, we look at how comic book writers would frequently reveal new detective mentors for Batman.
Source:https://www.cbr.com/batman-detective-mentors-henri-ducard-harvey-harris/