I drink milk and I'm the healthiest person I've ever met. I never get sick (and when I say never I mean like maybe once or twice a year).
Oh yeah, and that stuff about always washing your hands is a bunch of bullshit. I mean, yeah it's nice to have clean hands (no seriously, it disturbs me when they're dirty), but using soap and sanitizer ALL THE TIME will make you prone to disease. One reason I'm never sick is because I almost never use bandages, and I just let my wounds heal naturally.
Yeah, lactose is not natually digestable. It's subjective tho. People that can't digest it are called lactose intollerant.