When I see a blood donation drive, I will usually try to donate except if circumstances don't allow me to.
I've started donating blood since I was 19. My first attempt was 17, in which I failed for obvious reason. I was underaged and underweight.
Yesterday was my 7th time donating. I failed once few years ago as the nurse rejected me as a donor as my blood pressure was too low. The reason being that I can think of was that my sleep time was so uncertain as I was on shift, my sleeping hours were screwed, and I just had my night shift the day before.
So yeah it's time to replenish my blood. ^^