When it is raining lightly you do not need rain protection. The heat you generate is often more than enough to keep your shirt dry. Sometimes, when it is not too cold, and the rainfall does gets me wet, I take of my shirt. It takes less effort being disturbed by the wet and the cold than to fiddle around drying clothes after. My feet are most of the time already naked and they welcome the rain and the wet first. It makes an easier life not avoiding puddles, clinging on to fences not to get you shoes muddy, and make your way towards that bridge just to cross that small stream. Welcoming your body to the elements like this makes you roam more free. Your gear dictates less the way and demands less care and attention.
I believe it is healthy to expose myself to the cold the wet. I see it as a counter weight in training a healthy body. It also brings me a joy, a joy that comes with being more capable, more free, healthier and needing less.