[[WMG: Later in life, Mr. Collins and Elizabeth will have a torrid affair.]]

Elizabeth famously tells Darcy, "I had not known you a month before I felt that you were the last man in the world whom I could ever be prevailed on to marry." At the end of the book, he's the last man in the world whom she is prevailed on to marry. Sounds like perfectly straightforward foreshadowing, right?

Well, earlier in the book, she also told Mr. Collins "I am the last woman in the world who could make you [happy]." Draw your own conclusions.
** Pass the BrainBleach!

[[WMG: Mary and Mr. Collins were made for each other.]]
Mr. Collins is just too dense to realize this. (Some screen adaptations follow this logic, having Mary ineffectually pursue Mr. Collins.)

She'd make a good clergyman's wife; she could play the organ in church and teach Sunday School (that is, if they lived in the 20th century United States instead of Regency England).

[[WMG: The original book did have [[Literature/PrideAndPrejudiceAndZombies zombies in it]].]]

Jane Austen wrote the whole thing. The publishers just edited those parts out for the sake of not alienating their readership.

[[WMG: Mrs. Bennet has an anxiety/panic disorder.]]

I'm only putting this here because I believe I'll be laughed out of FridgeLogic, but Mrs. Bennet's descriptions of her symptoms sound an awful lot like a panic/anxiety attack, and she is demonstrably anxious about the idea of 'starving in the hedgerows'. Add to that that she just might be overwhelmed by the fact that she's gone from 'merchant class' to 'gentry', and not know what the heck to do in such a situation, and it seems reasonable to me.
* The assumption that she’s acting up “for attention” is a modern one. A woman in Mrs. Bennet’s circumstances could very much have been plunged into outright destitution in her circumstances, and every one of Austen’s early readers would have known that. She is ''legitimately'' afraid.