I wish it was just 1 coin. This was my sure thing so I could stay at home with my daughter. I feel so stupid. 
Never invest more than you can afford to lose.
No such thing as a sure thing.
Depending on how it is meant, this is a really stupid advice. Obviously it is a good idea not to invest money and thereby risk your short term liquidity. But when it comes to things like retirement, which you also can't afford to lose, how can you have money and not be invested? Name a single way to keep money safe and risk-free for 20 years!
Take me for example. I am a 'bear' around here yet 25% of my net worth is in bitcoin. Most people would consider a 25% investment into something to be ridiculous and foolish. I'm actually a bull but not enough to currently engage in being unreasonably leveraged into bitcoin.