The one that gets most of us is probably fear. Fear of losing, fear of missing out, fear of being wrong, fear of being right,... Ones decision making will be very poor when acting from a state of fear
Same as with trying to get f...d. Won’t do it through desperately buying them drinks at a bar. It will happen after you get drunk and relaxed, fall asleep, and wake up without your wallet.
Why are some painters true artists? Because they are guided by the heart, not the head. Anything that you want to achieve should not be done with a reward in mind. It must arise from your being. What you enjoy. Of what you like. It should be done for fun but never looking for a reward. Paradoxically when you have that focus, when you no longer want to win, when you give up the ego, when you don't care about the result, when you have a good time trading and don't even think about what you're doing, then it will happen.