My understanding is that the main correlation between sunlight and skin cancer is for sudden exposure to strong sun. If you go outside all year without sunblock

My understanding is that the main correlation between sunlight and skin cancer is for sudden exposure to strong sun. If you go outside all year without sunblock (as people used to do back in the day), and thus build up and maintain a natural tan, the cancer risk is very low. But if you sit inside all year and then suddenly go to the beach,l in July, the risk increases.