Because I'm beginning to think it's going to be me.
DS is 3.2 and still wakes every single night, several times. He wakes in a big panic, and needs patting back down (he cries out 'cuddle, big cuddle' before he is even properly awake).
My 7 week old DD sleeps better than DS does.
DH has been sleeping on the floor of DS's room for 2 months now, and we have achieved that DS stays in his own bed all night, but no sign at all of him staying asleep / settling himself without intervention.
DH is finding it hard to cope. We can't swap jobs because (1) I did the previous 3 years and (2) DH can't breastfeed DD, so she's my job!
So come on, tell me about your child who slept through at 3, 4, 5 years old, so I can keep the faith that it will happen, one day...