Can anyone recommend a 'Bayesian statistics the hard way' book?
https://onlinelibrary.wiley.com/doi/book/10.1002/97811192863...
Jaynes is certainly very deep and some sections are harder than others. It's interesting regardless of your level (this is a book worth rereading several times).
For a less technical, but full of insight, introduction see Dennis Lindley's Understanding Uncertainty:
https://onlinelibrary.wiley.com/doi/book/10.1002/97811186501...
[1]: https://www.amazon.com/Bayesian-Methods-Hackers-Probabilisti...
[1] http://camdavidsonpilon.github.io/Probabilistic-Programming-...
But really, the first two chapters aren't that hard.