My kingdom for some sleep

My mom likes to tell me that when she was breast feeding, she slept like the dead, often waking up in the morning in the exact same position that she laid down her head the night before.  This is pretty amazing to me for a couple of reasons.  First..what breast feeding mom with two babies under two gets to sleep all night?  And second, how did my far-from-relaxed, let's-be-as-up-tight-as-I-can-about-everything mom fall so easily into such a deep slumber? I try to believe I am a little more patient and laid back with my own two babies under two during daylight hours, but I find myself jumping at the slightest cry or whimper from their direction at night.  What would I give for five or six (or three) uninterrupted hours of sleep! 
I'm pretty sure both the 20 month old and the four month old will sleep for the rest of the night because now I am not.  The baby woke up an hour into the night and then the toddler woke up an hour later...and now I'm up watching the green light of the alarm clock and listening to my husband's slow steady breathing.  I recently heard about a mom who in one desperate act actually left her kids with her husband for the night and got a hotel room.  While I am actually a little jealous of her bravado, I could never do that.  I would lay awake in my hotel, knowing that I was blowing my one chance at total relaxation.  How lame is that?  On the bright side, I finally figured out what that thumping sound was I've been hearing for the past few months, so I'm not totally paranoid.  No one is stomping down the hall of our house to steal our sweet little cherubs and our neighbor is not rhythmically slamming his car door shut.  Nope, it's just the baby raising her legs and slamming them back down into the mattress.  Not sure why she couldn't do her exercises at a more reasonable hour, but I am glad she seems to value fitness.