heard this on howard stern this morning. serial killers were asked to solve this riddle. almost all of them got it right. the psychologists said the kind of thinking it took to get this right is indicative of a serial killer mentality. here goes my paraphrase of the question. -------------- a woman goes to her mothers funeral. there she meets the man of her dreams. the one she truly believes is her soul mate, etc. a few days later she kills her sister. why?