Milk It!

One of the many things I find fascinating about the Spanish language is the importance of the word milk, or leche. It is of course used to describe the white liquid that comes from mammals, but in addition to the literal meaning, such as café con leche (coffee with milk) it's also commonly used either as an exclamation or as part of an expression.

Here are some examples.

• importar tres leches - to mind three milks, which means to not care at all. For example, me importa tres leches qué opinas. I don't care at all what your opinion is.
• ser la leche - to be the milk, which means to be unbelievable or great. It can be used literally such as, Soy la leche, he aprobado todos los exámenes. I'm great, I passed all of my exams, or sarcastically, Eres la leche, macho. You're unbelievable, dude.
• de la leche - of the milk, which means more than a lot, as hell. Hoy hace un solazo de la leche. Today is sunny as hell.  Hace un calor de la leche. It's hot as hell. (I wish!)
• a toda leche - to all the milk, which means at full speed. Salimos corriendo a toda leche. We ran out at full speed.
• ¡leche! - dammit! ¡Leche! Me he pillado el dedo con la puerta. Dammit! I caught my finger in the door.
• estar de mala / buena leche - to be in a bad / good milk which refers to someone's mood. ¿Estas de buena o mala leche hoy? Are you in a good or bad mood today?
• tener leche en las venas (en vez de sangre) - to have milk in your veins (instead of blood), meaning you show no affection or you lack of drive.
• cagarse en la leche - to shit in the milk, which is what you do when angry.

Not sure why leche is so prevalent in the Spanish vernacular. Any ideas? Also, feel free to add more if there are. All this talk of milk is making me hungry for cereal.