For most of us, relationship with another is based on dependence, either economic or psychological. This dependence creates fear, breeds in us possessiveness, results in friction, suspicion, frustration.
Your sweetheart calls you by another's name. His eyes linger too long on your best friend. He talks with excitement about a girl at work. And the fire catches. Jealousy — that sickening combination of possessiveness, suspicion, rage, and humiliation — can overtake your mind and threaten your very core as you contemplate your rival.
Dirt used to be a badge of honor. Dirt used to look like work. But we've scrubbed the dirt off the face of work, and consequently we've created this suspicion of anything that's too dirty.