This review on Amazon, by Amanda M. Hayes, states that the reason the book is so insane is 'cause the entire Buendía family is the protagonist. It all makes sense now!
Family novels weren't a rarity even in realism.
If like many people you read this book at a young age, the insomnia plague will just be strange disease. But read it again, knowing about Alzheimer's Disease... and semantic dementia. Makes more sense now, don't it?
This novel either makes more sense if you know about other books of Gabriel García Márquez, or makes his other books have more sense. One event mentioned in the passing in the book, the very lavish funeral of Mama Grande, the madame of one of the brothels of Macondo, is both the title of both a short story and the book containing it. The short story shows that the woman was so influential and the event was so big that no one could have ignored it, but points that the Buendía family has very little to have with the deceased. Another book have a short story about a very old Rebeca de Buendía still refusing to sell her house, pointing reasons that are only understandable if you know her novel's backstory.