Yep I love sleeping, especially after a long days walk. I can sleep in many situations even under the 24 hour sunshine in Lapland (a Buff is your friend). As I have grown older, sleeping has remained easy, but rising in the morning as "fresh as a daisy" maybe more of a challenge. So the combination of mat and insulation for warmth is critical.
I recall that as a hiking youngster I slept on the ground with perhaps a newspaper underneath, however, I soon transitioned to a bracken (and other natural materials) stuffed hessian bag (a palliasse) which was an improvement over sleeping on the latest headlines. But I was not satisfied, so I began to explore other options, including testing the venerable Lilo which could do double duty for floating down rivers, an art well practiced in New South Wales on the Shoalhaven. I often wonder if liloing was the forerunner of pack rafting?