If you have a bacterial infection and your doctor prescribes you antibiotics, you should take all of the pills no matter what. When people start to feel better and decide they don't need the medication anymore, they are contributing to bacterial resistance to antibiotics. Even if you feel better after having a bacterial infection, some bacteria could be leftover. These are the strongest bacteria since they have survived throughout the attack by antibiotics, and if you don't finish them off they will proliferate into massive communities of ultra-powerful and resistant bacteria -- which you can spread to other people!!