Trees are not really trees

Sooo, what makes the connotation for a tree, and actual tree. It is only a tree by name. Humans gave it that name. It history was not as is, a tree might have been called a car, or a lamp. What I'm trying to say is, how can you really know if anything we know is true? Sure, you have science, religion, and all this bullshit. But how can you be sure? I mean, humans invented numbers. Not necessarily the quantities that number quantify, but the connotation of a the actual written amalgam of numbers. So, a tree to once species of intelligent life is a frog to another. Some moron decided a tree looked like a tree, so called it a tree. I also wonder how a computer works. It's some crazy ass fucked up shit, but they work. Yea, right click that shit, double click and paste that. Times new roman, fuck out of here. So, in another universe, and computer could be connotated as a tree, and a tree a computer. And Obama a good president.