You take one trade that you knew beforehand didn’t meet your trading plan criteria and boom, you’ve opened Pandora’s Box. Risking too much on a trade, more than you are comfortable with losing, is an excellent way to open the Pandora’s box of trading mistakes. So make sure you’ve learned enough to know what you’re trading strategy is and what a high-probability trading edge looks like so that you know when to trade and when to sit on your hands.