Most other people can make this post without breaking the rules, but if I make this post I will be breaking the rules
If I put: "I have never made the same post twice on r/truths" as the title and then "I've made a couple other different posts on r/truths but never the same one" as the body and then put the tag "fact checked by me so, it must be true", I will create a paradox because I've already made this post before. It will also mean I'm breaking the rules of this community because I am not telling a truth.
However, as long as you have never made a post identical to the one I've described on r/truths, and you've made at least 2 posts on r/truths that weren't completely identical, you will be able to make this same post without breaking the rules.
Therefore, I've created a post that you can post without breaking the rules, but i can't post without breaking the rules. I've also created a paradox.
Screeny for reference