I sleep on my stomach. I have been told for years that this is terrible for my back, but I honestly have no idea how you break yourself of sleep habits such as what position you sleep in. I find it a comfortable way to sleep for the most part. So do my cats.
I discovered early off in owning cats that, when they deem you worthy of there presence at night, that they will snuggle up to you and be little purring balls of heat against your side all night long. It really is sort of sweet and endearing. I actually like waking up to the feel of one of the cats curled against my side or behind the crook of my knee. I find it comforting.
That is until I want to move. Once I want to move they are nothing but a fuzzy interference in my sleep comfort. They turn from something endearing into a late night obstacle course for the sleep deprived. At moments like those I want to punt their purring fluffy butts across the room.
If you don't own cats you might not understand what the problem is. It is a cat, just move it. I only wish it were just that simple. If I could just move the furball I would. I have discovered however that cats develop some sort of feline super powers when they fall asleep.
You first have the lead kitty phenomenon. We will use my smallest cat, Etta, for this example. Etta weighs maybe three pounds. She, at a year and a half old, is very small. In reality she is mostly fur. She is easily scooped up without any effort. Once she goes to sleep it is a different story.
In her sleep my sweet little 3 pound cat feels more like she weighs 15 pounds. She also has her extra gravity or something because it is pretty much impossible to simply shove her out of the way. When she curls up behind my knee, which means she is between my legs, there is no way to just nudge her out of the way.
This leads into the second cat phenomenon which is kitty comforter surfing. When wanting to roll over or change position and you find yourself with a lead kitty engaged in their own gravity field, you really have no choice but just to flip over and not care if you crush the animal. It is a risk they take in sleeping in bed with you.
Only they are never crushed. Somehow as you twist and turn and the covers shift, they shift with it. They roll along the top as though they were easily riding the waves of the ocean. They may inexplicably weigh more in their sleep, but they are still pliable like putty. After all your moving about they are still settled in and sound asleep as though you hadn't just sent them rolling across the comforter.
In the end, after all of this effort, you are more awake than you want to be, only marginally comfortable, and the damn cat is still comfortably asleep behind your knee.
It is a damn good thing my cats are cute and fluffy.