Why does it sting? Is it to protect itself from herbivores, or may be to serve humans?
Here in Northern Wisconsin May, early June (before blooming actually) is a perfect time to collect nettles. When I pick them barehanded, I don’t mind an occasional sting, it feels good, it feels medicinal. In fact some people use the “urtication” method, when they deliberately whip themselves with nettle plant to achieve therapeutic effects. The blood circulation increases and becomes more efficient. Stagnation goes away and toxins get cleaned out faster. It is especially great for joints, backs and numb muscles.