Comment by didibus

> But I get skeptical when I see claims that we know how the universe began or how it will end

Absolutely, but you are interpreting it in the rewritten headline money making attention grabbing version.

The original version of the claims always say that from some observation, experiments, and projection from known models it derives that the universe likely began this way, or will end that way, etc.

That means, of all the going hypothesis, this might be the one with the best chances of being true, or close to the truth. It's not an absolute, but its the one that has the most chances due to the evidence behind it.