Are they 100% dependent on it to sleep? I am thinking I might need to get one for my three month old so that I am not always anxious about my two year old waking him up. So far, everything has gone good during nap time but there rooms are next door and I don't let her play in there during nap time. My fear is that this is one more thing I am going to have to pack up when we go places for the day. And I am also worried about ten years from now when he goes to a sleep over, will he need it then too? I am thinking if he only uses it during nap time and not a night, then maybe he won't be dependent.