Pretty simple. Post paradoxes. They can be of any sort you want. I'll start:
This sentence is a lie.
"I wish for you not to grant this wish," the man said to the genie.
If you drop a pencil, it needs to get halfway to the ground before reaching the ground, right? Well after that, it needs to get halfway again. And again. And again. And again. If there are infinite half-ways to the floor, it should never reach it. Yet it does.