People shouldn't have a supply for use when they feel like it. Antibiotics are a last resort, not first! If someone has some left over then they did not finish

People shouldn't have a supply for use when they feel like it. Antibiotics are a last resort, not first! If someone has some left over then they did not finish the previous course, which means that they have potentially allowed the strongest bacteria from the previous illness to live on. Maybe it's not common knowledge, but taking antibiotics is essentially putting evolution into overdrive. At first you kill off the weakest bacteria and then only later the most able to survive. If someone ends their course early, they are allowing the best adapted bacteria to live on and multiply. Perhaps the person wouldn't be getting sick the second time if they had finished their course in the first place. Also, taking antibiotics also does harm to a person's own flora, not just the invaders. So, please don't take antibiotics if you don't need them, and finish them when you do need to. Edit: removed extra 'not' in first paragraph.