DS has loads of soft toys. Until the last month he showed zero interest in any of them. We've gone through a major upheaval (moved out of our rental, renovating the new place and staying at SIL in the meantime) everyone is mega stressed and DS is picking up on it. Suddenly he's really attatched to "Bunny" and "Bear". I think some kids only form the attachment if they need that extra comfort and familiarity.