You have the flu. You spend the next seven-ish days in bed with a fever. You have gone through two boxes of tissues. Maybe you are also vomiting or have diarrhea, too. In other words, you are having lots of fun. On day eight, your body has done its job and the virus is gone. You may still feel tired and worn out, but your body has just ran a major marathon. Not only did your body get rid of the virus, but it also made you stronger.
Scientists have researched the flu virus in lab rats and have clearly shown that the antigens your body produces during the flu protect against cancer cells. How amazing is that? Here's another reason for you to be in awe of your design. Viruses are living organisms that we coexist with for a good reason, and it's not necessarily to torture us. There really is a reason for everything.
In case you like to read research articles, here's the link to the scientific study I mentioned. Click Here.