It's not hard to just cover your skin with clothing. I haven't used sunscreen in the last 10 years and generally have avoided any sun burn. I gauge how much sun I'm getting and just cover up. Each summer I get quite tan and can tolerate long periods of sun exposure before having to cover up (this increases over the course of the summer obviously). Fear of skin cancer is over blown and the increased sun exposure while avoiding sun burn will more than outweigh the risk with other benefits for health.

Despite that I´m an avid pro-cannabis user, yes, I do agree that we can live without it. That´s the best way to be healthy I guess, but well, us humans found ways to transcend mere animal life, so we might enjoy the trip then.