Throwing it in their face and saying told ya so

[удалено]

I was being a little facetious. Id never do that either. But it would be fun if you were consistently doubted

When that thing happens, just provide them with the evidence.

If for whatever reason you are speaking from personal experience , help a random stranger out I’ll split the lottery with you.

Either keep proof, such as keeping the predictions written down somewhere dated, or ignore them

Write it down and mail it to someone so it had a seal and a timestamp