In the 1980's a friend took up day trading. He was quite good at it, made a lot of money, had a very expensive custom home built, and as his success increased, he began leveraging more and more. In October 1987, he had swing trades in place that were levered to the hilt prior to leaving for vacation. If you're familiar with October 1987, you know the rest of the story: Black Monday, vacation was over and he had to liquidate EVERYTHING to cover the margin call.
I guess that's the downside of being a hugely successful beginner; you never learn what a "stop loss" is for.