1. You clap when the plane lands.
The origin of this practice is unknown. But it seems to only happen on flights to or from Russia.
2. You have a thick metal front door covered with fake leather, plus at least two locks, and it looks completely normal to you.
It is for protection, but you are not sure from what.
3. You have seen or own at least one key the length of your palm.
You do not know why you need an old-school key like this, but in Russia, you do not ask “why?”