This is also a semantic problem, what means "to afford"? Different people have different concepts regarding what exactly it means.

I'm personally quite bullish on bitcoin, so I couldn't give an advice "don't invest more than you can't afford" in a clear conscience. On the contrary, I think it is fine for someone to borrow money to invest in Bitcoin now, if that person made his homework and believes that the price must go up with reasonably high probability. IMHO, it is not the same as lottery, where you have no chance to predict what will happen.

OP: No, I don't think you are an idiot.