My resident hubby and I were having this conversation today, because he was complaining about always being exhausted from residency, never feeling like he has satisfying sleep, and always feeling worn down and exhausted so he doesn't feel he does a good job on studying or having fun.
This led me to think about the question of low energy people vs. high energy people. Which one are you? I am definitely low energy. I tend to gravitate toward low energy activities, such as watching movies, the computer, etc. rather than going out and doing something active, like working out, etc. I once dated a guy who was totally high energy. He was always on the go, couldn't stand to sit still, and would be unable to sit and read a book for a couple of hours, or do anything that involved sitting in one place for awhile without doing something else.
Some of DH's resident friends get up early in the morning (like at 4 am) and work out, or work out after work, and then have the energy to go out on the town. I would never have the energy to do that. In fact, I find I often don't have the energy to do the things I want to do, like clean the apartment after work. I'm just too tired. I've always been like this, ever since high school.
I also like to sleep a lot--10-12 hours to feel my best--and take a lot of naps. My hubby is exactly the same way. Personally, I feel that in terms of energy levels, in relationships, opposites do not attract.