Oh Yes, This Is Bliss

Okay, I suppose you can define bliss…"euphoria, utter joy, supreme contentment." But how to explain it? How to understand what brings it on? 

A sunny, warm, blue-sky day.  Bare trees pushing upward. Little green shoots in the ground. Birds hopping, flying and chirping. No compelling reason to do anything but sit still and breathe. An ocean of good feeling floods my body. Unexplainable. Oh yes, this is bliss.