I could only let DD1 cry herself to sleep IF I was cuddling her. In that case I was trying to get her to drop her night feed and although she was crying I was cuddling and soothing her without the feed - fortunately it lasted only a couple of nights before she stopped waking BUT even doing it that way was not pleasant and I was also teary. I don't think I could ever let my babies cry alone for that length of time and not provide comfort