Learning new things is HARD. Stats methods are particularly hard because it not just about running the test. You have to… learn when to run the test learn how to run the test learn how to interpret the test AND learn how to write about the results of the test Part of what makes this learning hard is that our research methods training has drummed into us that there is a RIGHT WAY TO DO IT.
When we want to learn how to do something new in R, we all start by googling it. Having worked out simple ANOVA, next on my list is repeated measures. Domnique Makowski has an excellent blog post that comes up at the top of the search results when you google “how to do repeated measures ANOVA in R”. He lures you in with a post that seems like it is going to solve all your problems and then and BAM… starts the post by saying “DON’T do it”.