If your twin's going away for 20 years to fly around space at close to the speed of light, they'll be 20 years older when they come back.
A spinning gyroscope, when pushed, will react in a way that makes sense.
If another nation can't do anything as well as your nation, there is no self-serving reason to trade with them.
You shouldn't bother switching in the Monty Hall problem
The sun moves across the sky because it's moving.
EDIT Corrected all statements to be false
Open trade [...]
I think you may have expressed this one the wrong way around; the way you've phrased it ("can make you better off") is the surprising truth, not the surprising untruth.
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
Notes for future OT posters:
1. Please add the 'open_thread' tag.
2. Check if there is an active Open Thread before posting a new one.
3. Open Threads should be posted in Discussion, and not Main.
4. Open Threads should start on Monday, and end on Sunday.