Girls, hi everyone. Question: I find it very comfortable to sleep on my…

Girls, hi everyone. Question: I find it very comfortable to sleep on my back — I really sleep well that way, but I mostly sleep on my side, of course. Does anyone know why? Usually sleeping on your back was uncomfortable and even bad, but for me it's the opposite and my tummy also calms down. And on my side it's always a struggle ? Does anyone else have such quirks?