I was under the impression that the "this is definitely not a book for beginners" was the standard consensus here: I seem to recall seeing some heavily-upvoted comments saying that you should be approximately at the level of a math/stats graduate student before reading it. I couldn't find them with a quick search, but here's one comment that explicitly recommends another book over it.

I think it's even better if you're not familiar with frequentist statistics because you won't have to unlearn it first, but I know many people here disagree.