Doesn't really work. There are event horizons. Anywhere far enough away is never going to hear about your brilliant ideas.

And the Big Rip puts the kibosh on it even more thoroughly. Eventually no two neurons in your brain can ever make contact again.

For a little-known mindboggler, look for E.A. Milne's article on the age of the universe. I think it was published around 1920 and it puts the boot into lazy common sense with elegant thoroughness. It doesn't even need general relativity to do it, special gets quite weird enough.