I don’t particularly have a problem getting up, but if there’s a weekend where I have no reason to get up, I could lie there and doze all day.
This I suspect may well be an urban mythorama, but sure I heard recently that Einstein never slept a full night’s sleep in his adult life, whenever he felt tired he would sit in a comfy chair with a pencil in his hand and have a nap, when he got to the edge of deep sleep his hand would relax, drop the pencil onto his wooden floor and the noise would wake up up, and off he went for another couple of hours’ hard thinking.
I have also read somewhere that back in the day we used to have two shorter sleeps during the night with a break in the middle, rather than sleeping through.