When the 'just one more' trade becomes 'just lost more'

I had a decent run going on $EURUSD early last year, everything was clicking. Then, against my own rules, I decided to take one last trade before shutting down for the day, feeling invincible after a string of greens. Saw a quick wick on the 15m, thought 'easy scalp'. It wasn't. That one trade quickly spiraled into a series of revenge trades, each one digging the hole deeper until I'd given back a significant chunk of the week's profit. The market, as it often does, decided to teach me a lesson about hubris and sticking to my pre-defined limits. Never underestimate the power of a few bad decisions in a row to wipe out careful work.