The lesson of 'just one more trade'

Thought I had the market figured out last week, closed out a good day green, then convinced myself there was 'one more trade' left in $AAPL. Chased a breakout that promptly reversed, wiped out half my earlier gains. It wasn't about the setup; it was pure greed and not respecting my own rules for stopping. Ended up giving back money I'd already earned. Classic overtrading mistake. Set limits and stick to them, no matter how good you feel.