21

A rather arbitrary age (even more so than 18) used when it comes to adulthood. It is also the drinking age in America (America having one of the oldest drinking ages in the world, and the main reason why it was raised at 21 was to prevent drunk driving that was going on at the time).

You can go to war at 18 but can only drink at 21 in America? The inconsistency is strong with this one.

21

21 is a meme

What’s 9+10 ...... 21?!

21

The greatest number in the world that can control everybody
Rumored to be the source of nolanitis

it the greatest thing I've ever seen in my life!
21!!! next to a 21!!!

21

Your that person who got 10 + 9 wrong. Why is this meme so popular.

This one random boy: Whats 10 + 9?
This other random boy: 21
This one random boy: you stoopid

21

The time in your life when your finally LEGALLY alowed to drink.

We all know you drink and your like 15...

sneaky human

IM A HUMAN BECAUSE IM 21

21

The other 21 in a meme.

9+10=21 is a popular meme now these days.

21

The summation of 9 and 10.

Professor: “You stupid.”
You: “No I’m not.”
Professor: “What is the summation of 9 and 10?”
You: “21”
Professor: “Very well done! You have clearly demonstrated proficiency in summation.”