You want my blood...

I had some blood taken from me today, and I honestly can't remember the last time I lost blood. Which is kind of amazing, being that I play football and basketball, but I have escaped those games without a cut or deep scratch. It's possible of course that I cut myself last week, and just don't remember. But as far as I can remember I don't know the last time blood left my body. Until today, when I lost 4 vials worth.