It was greed that caused this to happen. Investing money you can't afford to lose is like betting on horse racing. Sometimes you win,but don't expect anyone to feel sorry for you when you lose.
Only a damn fool invests money they can't afford to lose. It is nothing less than legalized gambling. If you want to do it,start small and then invest your WINNINGS,not your savings. THAT is how you make your money work for you,and if it doesn't work,you aren't ruined.
BTW,this was a lesson I learned when I was 18. Gambling is like drinking. Some people can do it,and some people lose their freaking minds trying to do it.
Regardless of who you are,you do NOT bet/invest money you can't afford to lose,period.