You should keep two things in mind: (1) Authors are only human beings, and (2) one book doesn't equal one tidy emotional climax, or monolithic point of it all.
On (1), for various reasons our culture takes literature as a cult of heroic genius. Every famous author, every "canonical" name, isn't taken in historical context as a human being with a unique mind full of unique elements and motivations, but a Genius who is supposed to produce Works of Genius. The truth is, great authors wrote shitty or mediocre books, authors can be famous for strange reasons, or not be famous until years after their deaths, and authors can have redundant and rambling literary styles. A good example is Les Miserables, which was considered saccharine and disappointing by many contemporaries. Zola is considered by many to be a genius, but Lukacs considered him a second-rate talent; Lukacs considers Flaubert to be a genius for certain reasons, but many consider Flaubert mediocre.
When you read, you should not be trying to access the singular Genius Essence at the gooey centre of the book. Just treat it as something written by a purportedly very smart guy. It can be redundant, it can be genius but have shitty redundant parts, it can be genius but flawed, etc.
On (2) more specifically, you should allow for the possibility that your mind has been trained to expect easy and predictable gratification. Movies and other modern narrative forms are extremely simplified and can be almost childlike. It's similar to what has happened to modern music, where the innovations of the classical tradition reached a point where they required cultivation to appreciate, and then capitalism moved in, crudely extracted the "sweet spots" that are easy for anybody to enjoy, refined them to the point that they could be reproduced easily, and then bombarded people with them from birth until expectations were permanently lowered.
A book is the horizon of another world, a point of contact that opens up a space where you can think of something other than that is already in your head. A movie, by contrast, is designed to meld with your already existing space of expectations, and entertain you for an hour. You should be more scared of ready-made and easily induced "heights" than of boredom. Boredom is at least forcing you to think and opening up the possibility of learning something completely new.
Also, after you read enough, the spaces opened up in your mind by books will start to fuse with each other and with your historical knowledge of the context in which they were written, and even the boring parts of Flaubert or Moby Dick can start to be a bridge to insights whose possibility you hadn't realised before. You start to inhabit the same space as Flaubert did when he wrote, or as his contemporaries did when they read him, and you'll start to see surprising things.