I took me a couple years and one persuasive friend, but I finally did it: I gave blood.
Being a bit squeamish, the idea of blood rushing of out my body into a tube never seemed like a good idea. I held a fear that I'd pass out, freak out, or hurt myself... until I stopped being so dramatic, finally lay on the table and let them stick that needle in me.
I breathed frantically for a little bit, overwhelmed with stress, paranoia and self pity. I kept thinking that, over on that side of myself I dare not look, a tube was carrying blood from my body to a plastic bag. After about a minute, I told myself to suck it up, and I got over it.
That blood may someday be used to help save a life. Somehow, that notion escaped me for several years. Perhaps I was too self-absorbed to think beyond how that action would effect me to think about the good it might do for someone else.
For anyone who hasn't, but is able to, I suggest giving blood. Set any invalid accuses aside, and just do it; you'll be helping others and feel great about it. It might be crazy and slightly morbid, but the thought of my blood in someone else's body is incredible. In a small way, it brings you a little bit closer to everyone else - all those people you know and all those you'll never meet.