DS was about 5 when I had DD. After her, we talked about (and ended up actually doing it) getting my tubes tied. Well, apparently kids hear much more than you think! DS went around asking every woman he saw (teacher included) if she had her tubes tied! Right after that operation for my tubal, my dr. told me "no coochie coochie for 2 weeks" apparently I repeated this to someone, because a few weeks later I was playing with the baby and said "coochie coochie coo" and my DS said "HEY MOM! Your dr. said no coochie coochie for two weeks!"
Forward a year or so, DS was playing with his little sister and there were dollies all over. I hear him shout "I knew you should've got your tubes tied! Look at all these babies!!"

One time when DS was real little, all his toys and stuffed things seemed to talk and take batteries. My DH was watching a hunting show and a deer was shot and fell down, DS said "oops, his batteries are dead!"

Recently DD was putting away silverware and came across a measuringspoon that doesn't go in the silverware drawer, she asked me "where does this one live?"

Back in 1995 I did childcare in my home. The story an above poster wrote reminded me of this. I was reading a story on the holidays. It came to Christmas and told of baby Jesus. One little boy said "oh oh, I don't like that word" I explained about Jesus and said it is not supposed to be a bad word, it is God's son. Another little boy knowingly nodded and said "yeah, and all the other swear words are God's brothers!"