Your personal Tumblr journey starts here
Short answer is that each tab is its own process. Since different processes get their own chunk of memory they can use and can't change anything outside of their chunk, this prevents tabs from altering each other. As you can imagine the security implications of that would be Bad.
Not only are you yelling at a poor mother and many adorable children, they've been guarding your house from spooky monsters you can't see this whole time!!
if any of you could tell me why task manager thinks i have 13 firefoxes open at once that would be great