I have to say, I'm kind of dense and didn't realize anything until my DS's teacher in 3rd grade suggested he be tested. But then again, my kids haven't done anything consistently that shocks and amazes.. however looking back he came home from preschool around age 4 and told me that "plants are green because of chlorophyll." Prior to that he was a late talker, but was pretty amazing at puzzles (around age 2-3). I can also remember that he read a book in 1st grade (the Fantastic Mr. Fox) and he had to summarize the story in front of the class. It was a little weird when he summarized by telling the story exactly as it had been read to him (word for word, exact dialogue from book, he'd memorized it after one reading). So there were flashes of "hmm that's odd/cute/etc." I still keep thinking he's not gifted but he was paired up with this other kid at school for Science Olympiad who really could be his clone in interests, quirky mannerisms, etc., and surprise! the other kid is highly gifted.
Sleep, I'm sorry to say, is still an ongoing problem with my DS. My DD is a lot better though.
