Sleeping through the night

I am not sure why this is a coveted phenomenon- I am not particularly a fan. At eight months, Liam's status quo is to wake up once, usually around 5am, nurse and go back to sleep for a couple of hours. Occasionally, however, he will sleep the entire 12 hours uninterrupted- for him. I generally wake up and toss and turn waiting for him to stir. Then come the crazy thoughts- is he okay, is his leg caught in the crib, is he suffocating in his blanket, is he even in there anymore? Neurotic, I realize but 12 hours is a long time to go without hearing a peep from your baby. I've started getting nostalgic for the first nights when every few hours he would call out "mom, dad- I am here, I need you." That wasn't that long ago after all, so I don't think it is unreasonable for me to get unnerved during an entire night of silence. If only I had the luxury of twelve hours of sleep- I am pretty sure the last time that happened, I was eight months old.