You find it slightly annoying that a completely static page causes the web server to run code? You want to shave off a few milliseconds from the page load time? Your page does not have dynamic content for your visitors? You have a static IP address at home? You are okay with slightly hackish solutions that might break spectacularly in the future?

Then I might have a short guide to caching PHP requests in Nginx for you:
https://guides.lw1.at/books/how-to-cache-a-php-page-using-nginx