Illness reveals the man's character

As the saying goes, 'There is nothing like illness to discern the hearts of others.' Those who are usually affable but drift away when you are down with an illness or are enduring hardship are not nice fellows. You should be considerate to a suffering man, and pay the poor chap a visit, or send gifts to cheer him up. Never spurn a person who has shown your favour in the past. This is how you can fathom the measure of a man. Many in this world seek comfort when they are in need, but don't give their benefactors a second thought afterwards. 

Hagakure