We all learned about our circulation and digestive systems from school, but those are child’s play in terms of complexity in comparison with our immune system, which my high school biology teacher just taught it along the lines of “something something white blood cell something something,” which, as it turns out, doesn’t even scratch the surface.

(To be fair, though, if my teacher had tried to explain immune system properly, he would have spent years teaching nothing else in his biology class, because it is so hopeless complex. And a majority of my high school classmates, myself included, would have probably flunked that class too.)

Thankfully, Philipp Dettmer, the founder of the YouTube channel Kurzgesagt, has done a wonderful job simplifying it for non-biologists like me, making an extremely complicated and convoluted subject somewhat relatable. I am in awe of how everything worked together to keep us alive. While it’s likely I will soon forget about the relationships between the Macrophages, Dendritic cells, MHC molecules, cytokines, B cells, T cells, etc., how he successfully debunked a lot of long-standing health myths in the book will likely stay with me forever:

• So you have probably heard that you have white blood cells and they are your immune cells or something like that. … “White blood cells” describes so many different cells that do so many different things that it is sort of useless if you want to understand what is really going on here.

• There is a vicious part of measles that is not discussed as much as the disease itself: Kids who overcome a measles infection have a higher chance of getting other diseases afterwards because the measles virus kills Memory Cells. … The virus basically deletes your acquired immunity. … Being infected with measles erases the capacity of the immune system to protect you from the diseases that you overcame in the past. Even worse, a measles infection can wipe away the protection that you might have gained from other vaccines, since most vaccines create memory cells. Therefore, in the case of measles, what does not kill you makes you weaker, not stronger.

• After decades of research it has become clear that with an extremely high certainty, your attitude has no effect on your chances of surviving cancer. … It is a terrible thing to say to someone with cancer that their attitude matters and that they should stay positive, because it does two things: For one, it puts the responsibility of healing and surviving on the sick person. It implies that if you don’t win the fight and have faced the gravest of all outcomes, it is your fault. … The other reason is chemotherapy, surgeries, and radiation therapy are, well, not a great experience. And by being told that you are supposed to be positive to get well, you are told that you are not allowed to feel how you feel.

• At least for now, there are no scientifically proven ways to directly boost your immune system with any products that are easily available. And if there were, it would be very dangerous to use them without medical supervision.

If you are at all curious about how we manage to keep ourselves alive despite all the pathogens around us, read this book. You’ll thank yourself for it.