My husband has always gotten a lot more sleep than I have. In PART, because he needs more. He's a towering nightmare if he doesn't get enough sleep, and being woken in the middle of night... well... lets just say we don't do it.
As a young family I figured this was just a strength/weakness thing.
Because while I revel in sleep... I don't really need it as much *as long as* I can catch up from time to time. I can do 3 hours on a regular basis and function fairly normally for a few months before the prolonged sleep dep starts to kick in. On 4-7 I function completely normally. I'm "happy" woken up multiple times at night (not happy to wake up, but I come awake very quickly and am alert/myself, and can smile/ hug/ talk rationally/ think coherently). Also, I can sleep in a chair, on the floor, show me a semi-flat space and I can sleep on it.
So my 'strength' in being able to sleep fairly flexibly I figured matched up with his 'weakness' of needing exactly 8 uninterrupted hours in one particular spot. The same way several of his strengths have matched up with my weaknesses.
Come to find, I was just being used and disrespected, but that's my husband for ya... and a different set of issues altogether. That my sleep and well being is completely and totally unimportant to him compared to his sleep and wellbeing is just par for the course.
But in one way it was nice: Since he NEVER helped at night, I didn't expect him to. I got the same amount of sleep I would have gotten (and did get) when he was gone. At least in my own life, I've learned that unmet expectations/hopes hurt one whole heckuva lot more than reality. As in, as long as I knew I was on my own, I was a lot happier than when I kept waiting for him to help me and being disappointed that he didn't, or afraid that he wouldn't.
I do, on occasion, hire someone to watch my son for the day so that I can catch up on missed sleep. Absolute. Heaven.