I used to have a massive one- volume book containing the complete works of William Shakespeare. I owned it for years. I took it on trips. It was dense and impressive. But I never read it. It was too big. Whenever I wanted to read a play, I bought it in a single volume. This way it was not only portable and manageable, but pleasurable. The words weren’t in small fonts jammed in double columns. I could read not just for sense but as a sensory experience.
This same issue exists with poetry anthologies. As wonderful as books like Norton anthologies are and as cool and important as they look on the shelf, I suspect few people read them for pleasure. We buy them and haul them around for classes or use them for reference. In trying to be as comprehensive as possible, they sacrifice readability.
For many people, the poetry they read is in these texts. They do so because it’s assigned for a class, and usually they’re required to read dozens at once.
The problem is that a poem is a remarkable condensed and efficient delivery system. It’s the equivalent of a cigarette or a Belgian chocolate. It gives an intense emotional charge in a short period of time. So, too many too quickly will become overwhelming. Chain-smoke a pack of cigarettes, and you’ll feel nauseous. Eat a box of chocolates in one sitting, and you’ll feel sick. Poems are the same. Furthermore, even if each of those chocolates is distinctly different, you won’t be able to sort them out. They’ll blend together.
Novels can create their own space, entire universes, in which the reader can move around. A poem works differently. It may be that a book ingests a reader, but a reader ingests a poem.
Consequently, poems need to be read in small doses. To switch the metaphor to medicine, if a small amount of medicine is good for you and will heal you, that doesn’t mean a large amount taken at once will make you superhuman. Just the opposite. It usually will harm you.
So, maybe books of poems should have warnings or advice like on medicine or bottles of wine. For a healthy, fulfilling, lifestyle, take in moderation.