Macroman, if the flu wasn't contagious, then I would have no problem with the people who want to suffer the consequences of not taking the shot. But since the flu is contagious, you are at risk of giving it to other people and getting them sick for no reason.
Shakaka, there is no shortage of flu shots. Also, you clearly just made up the statistic about how it only works 10-20% of the time, on the spot. If that was the case, then the Center For Disease Control would not have stated that the flu shot is, in fact, effective(source:
http://www.cdc.gov/flu/protect/keyfacts.htm); because I believe that if it only worked 10-20%, it wouldn't be effective. It also makes more sense for you to take it, since you will have responsibilities and roles in your country as you grow up. As for the old people, they are already old and have served their purpose in this world(if any), and they will be leaving this world chances are before most people your age will leave. You live on, you serve your role, you get the shot(if its between you and her). They are old, they already served their role, they are leaving this world soon anyways, they shouldn't be number one on the list to get the shot. By the way, when you are young and your body is still building, your immune system is weaker than the bodies of older people; thats why most people die of cancer when they get it when they're young, and older people fight it off better.