The syntax blocker is the biggest one for me. Are there books full of classic proofs and explanations of their syntax and shorthand? I'd be very interested.
Since syntax – as opposed to the mathematical facts expressed thereby – is usually considered something not worth learning by heart, I doubt that you will find a book that collects proofs in their syntax of original publication and then explains that syntax.
In particular the section on set theory is important (element of, subset, etc..) and the two qualifiers: for all, and there exists. Here is a 6 page primer on set notation, which contains a simple proof http://mcgillweb.alwaysdata.net/set_notation.pdf
Grab a copy of "Proofs from the Book". It's tremendous.