One of the biggest problems I think is that most experienced mathematicians seem to forget that the written forms of mathematical systems contain significantly

One of the biggest problems I think is that most experienced mathematicians seem to forget that the written forms of mathematical systems contain significantly shortened symbology which requires significant understanding of what is NOT written explicitly​. The most basic example I can think of is "ab" meaning "a x b" but the "times" function has been deleted but still needs to be understood. I find when reading mathematical books I cannot follow examples and progressions to the next level then the next level etc as at every progression there are significant pieces of information that are missing yet text books rarely if ever mention what is not written, so how can the novice possibly figure it out.