Ode to sleep

How can someone who has been up all night and then all the way up and out of bed at 5 be in a good mood? I would love to find out so I can replicate this feat. I was up most of the night, and then out of bed at 7 and am not particularly pleasant, and J was up most of the night and up at 5 and was most definitely not pleasant at all. So, how does the sleepless monster do it? And I suppose a why would be in order. Todays sleepless monster is S. H had her sleepless moments, believe me, but she is now a champion sleeper. H never napped, even as a newborn. She didn't sleep through the night until after she was a year old. I've blocked it out, but I'm pretty sure is was way after a year old, maybe closer to 2. H's sleeplessness hit us hard because we were not already exhausted by one child when she came along. We were used to leisurely mornings and sleeping late if we stayed up too late. I am not even asking for that- I would just like to sleep for some consecutive hours.
This is on my mind largely because we have been getting more sleep in the last few weeks thanks to the generosity of our family. J's parents get up with the girls whenever they're here or we're there, my mom had them sleep over her house. I was actually well rested on new years eve day, the girls had slept over at my mothers house the night before and I felt so sharp, so awake- it was making me nervous, actually. I kept thinking, whats wrong with me? Whats with this energy? Then it hit me, I had gotten to sleep the night before, all the way through the night- and had woken up when I was ready to, not jolted awake by the chainsaw yell of S- which is how I'm woken up most mornings. (She really does sound like a chainsaw. Once they were doing some work on trees down the street while S was napping, and I went up to get her- she was sound asleep. It was the chainsaws I heard.)
I have been functioning exhausted for so long now, and I know I'm not alone in this, that its the new normal. Well, not that new- but I'm still working on what it means to feel like you're on speed when in reality you have gotten a night sleep. I probably won't have to worry about that for a while.