If you sit for a long time on the bank of the river, you can see how, past you, the corpse of your enemy floats.

What a proverb. I did a little research and it seems it was Sun Tzu (philosopher), the Chinese author of The Art of War who made it, but the Japanese all read it during the Samurai period.

The JAHM coin is indeed in the subway where many can't see it, but people like me and you have patience, and I think that is what the proverb is talking about mostly.