Of course it's hard to believe, because it's a blatant lie.
How do you know it's a blatant lie? You assume, but time will pass and this profitability will turn out to be real. What would you do then? Will you regret not believing in this astonishing profitability?
Welcome to the way of the world. Do your best to convince with 'concretion' of your proposition.
@DireWolfM14, plenty on plenty of cryptoassets have done 30x's. I'm sure one received their fair share of "that's a lie" if any claims of such returns were made before any substantial increase in price..