You can only remember 4 things at a time.
31
If you're over 100 years old, there's an 80% chance you're a woman.
143
It took 200,000 years for humans to reach 3 billion in number. It took 40 years for the next 3 billion.
11
About 3000 years ago, most Egyptians died by the time they were 30!
18
A person swallows approximately 295 times while eating dinner.
63
Someone on Earth reports seeing a UFO every three minutes.
180