What is best here depends on the passage being read and how often awkward passages occur. Return to awkward words, phrases and sections later. If you do this as you read and reread, you should see the number of items to revisit get smaller 2 . You may then uncover most and perhaps all the ideas new to you in the book. Remember that in the search for ideas new to you, your aim in reading should be to understand the meaning of every word, every sentence and every example.
Details are important.
Every meaning not mastered hides an idea new to you. Your ability to understand ideas or master skills depends on your mood and perhaps the hour. So skip the hard passages. Relax and take a small break. Afterwards return to the omitted passages in a different and fresher mood.