Causes of Head Wounds Which Have Drawn Blood

I hit my head today. It hurt a lot, but mostly pride until I verified that I was bleeding. So my brain's working about 20% efficiency. Enjoy a thematically related list.

Causes of Head Wounds Which Have Drawn Blood:

• Glass shelf (little blood)
  
• Cat bite (surprising amount of blood compared to size of puncture)
  
• Mid-air collision with another Jew (profuse bleeding)

It occurs to me Jews might be our own antimatter. It'd explain why we complain so much in close proximity to each other: we sense impending annihilation. Also why we're historically combustible.