There are 2136 characters officially designated as "Kanji for everyday use". To read a newspaper one needs to know between 2000-3000 characters.
The characters for RIVER and BIG (below) are important! Japanese toilets have "little flush and big flush" buttons or levers labeled only in Kanji.
Knowing "mouth" makes it easy to walk right into a place through it's "mouth".
Wedding arrangements can be written in seven characters! (Hey kids, found a great place for a reception... a Buddhist temple/Shinto Shrine complex! Ha! Just kidding!)
My personal favorite: fire extinguisher. Easy! First character is a three-story building with flames coming from the roof. Second character is a person running for a fire extinguisher. Third character is destroyed building rebuilt with gable roof and two satellite dishes.
Wiggly line means hand rail (in subway)!