how much have you heard?
what'd be the craziest the most reasonable thing you've heard of this bitcoins thing?  

 It is run by some Saratoshi guy, he will take all your money. 

 He could also take all your marbles 

 you know, bit of coins. 

 "you put the coins in the bit, some maths happen, et voilá!"
something alike? 
could be fair put 🤔  

 precisely that! 

 I've heard is nerd stuff. 

 it is, yes. but it also has some pleb stuff 

 Don't doubt it. 

 It’s magic internet money 🪄 🛜 💰 

 It’s like gold that you can email. 

 It’s worthless garbage.  I’ll take what you’ve got no charge 

 Basically you buy some, do nothing with it, and say stay humble while being incredibly smug.  

 its rat poison, stay away 

 It’s about hopium. 

 You don't need permission to hold a number no one can guess. 

Sorry, I couldn't think of anything funny.