I’m not a blood donor. I haven’t been since August 11th 2000. Apparently, there’s a small chance I may have contracted mad cow disease (Variant Creutzfeldt-Jakob Disease or VCJD).
Tell people you’ve previously been afflicted with Dengue Fever, Glandular Fever, Ebola, or various other tropical and sexually transmitted diseases: no problem.
Tell people you previously lived in the United Kingdom (between 1980 and 1996) and occasionally enjoyed your roast beef and Yorkshire pudding, forget it pal, you’re tainted for life, even if you do have a relatively rare (AB Rhesus Negative) blood group.
“AB is considered the worst blood type. In predictability-loving Japan, they’re loose cannons. They also like to set their own conditions and reserve the right to drop out when things don’t meet their expectations. They’re known to be sensitive and considerate—at times—but it just isn’t enough to balance out the flaws in this blood type.” (from Issendai.com)