It's always been " invest what you can afford to lose" it pays to be courageous sometimes but it is going to be so costly and you could lose everything because of the market volatility, even experts are losing money, that is why it's important to invest what you can afford to lose, do not gamble your savings away.
I think in the context "courageous" the poster meant being strong in mind to withstand any form of disappointment or pressure crypto might bring not necessarily being over smart, which is the meaning I understand from your reply.