Or: Get Better Soon
Feel Better
Quick question for you: Why does being sick give us unpleasant symptoms? Believe it or not, usually it's not the specific illness causing all those symptoms (though they certainly cause some.)
Fever would be the classic example here. Infections don't actually cause fevers. Instead, fevers are a defensive mechanism used by the body—most pathogens can only survive in fairly specific temperature ranges. Raising body temperatures is a good way to kill them off.
There's a more interesting series of reactions to infectious illness, however, known as “sickness behavior.” Fatigue, aches, chills, depression, irritability, nausea, and disinterest in socializing, among other symptoms, are all counted as sickness behavior. These symptoms show up again and again across countless diseases, and they're very seldom caused by the disease itself. (And they're not just in your head. The symptoms are physiologically very real.)
It turns out that there might actually be an evolutionary advantage to these symptoms. While they don't help kill invading pathogens directly, they do serve a specific purpose: they keep you away from other people.
If you're not interested in being around other people, you're less likely to spread illnesses to others, including those in your family group. Early humans or human ancestor species who lacked sickness behavior symptoms likely would have just wandered around and hung out with other, non-sick people, infecting them more frequently. Even if those individuals who lacked sickness behavior symptoms were better able to survive disease themselves (which there is no indication that they would’ve been), they'd still be less likely to pass on their genes.
This relates back to an idea known as evolutionary altruism—namely, that evolutionary survival and adaptation doesn't just happen on a personal level but also on a community level. Many behaviors that don't advantage the individual, or often even their family at all, end up being incredibly evolutionarily advantageous for the species. So, in the case of getting sick, the extra suffering is there to help others.
Moral of the story? Anyone who tries to claim that survival of the fittest means they don't have to be charitable and help others is full of it. Also, they don't understand natural selection. Survival of the fittest is actually a misinterpretation of Darwin's theory, but that's a story for another day.
