"That you can get water by c*****g open a cactus and drinking the liquid inside. Unless you are a botanist who can identify the one or two specific types of cactus that are safe, you're going to have a bad time. The fluid in most cacti is full of acids and alkaloids that will make you violently ill. You'll end up vomiting, which will make you lose way more water than you gained and speed up the dehydration process."