"Words mean whatever I say they mean" is not the best argument tbh https://twitter.com/LibbyLovess/status/1290260036376317953

We will be letting this individual remain ignorant in peace. You can lead a dead horse to water but beating it won't make it drink.

Anyway if you actually want to learn about phrases you didn't realize were racist - and there are a bunch - I suggest googling "words you didn't realize were racist" and reading up.

But be mindful of what you find there, too. This article has a couple good ones, but also... there is no comparison between "hooligan" and "bugger" to something like "sold down the river" https://www.businessinsider.com/offensive-phrases-that-people-still-use-2013-11#11-hip-hip-hooray-11