Example of random thought

A person is most healthy when their bodies are stimulated right? weather it be a muscles, or lungs, or the foods they eat, anything really, but stimulation is key to survival, and sanity. So I came across a thought, what about tanning? the sun on a person's skin, is that not stimulating? I guess this is a question that will probably only get answered in death, but it is truly baffling. Just think about it, it doesn't make any sense that it should be bad, for one thing, let alone bad enough to cause cancer! Ok so first off, being in the sun makes freckles come out, which are cute on anyone! It makes skin bronze and glowing, clears up acne and builds confidence! All of these positive effects greatly outnumber the negative ones, yet it's result is skin cancer? really?