Discipline in trading is especially hard for forex traders

I love trading forex due to many reason one being the high volatility. You almost always get second chances for entries and exits. Prices tends to oscillate around their "fair value" al to more than in Stocks or ETF´s. There is almost no pair the rallies 50% in a year.
While there are scenarios for early exit, one should only execute such planed exceptions right? But even after 12 years of trading my n°1 mistake remain early profit taking!