Absolutely, it's the thing I struggle with the most, every time I mess with the plan it backfires, always :-) That's why I've forced myself now to put on a trade with a profit and loss target and walk away.

You can drive yourself insane second guessing every trade, thinking you've made a mistake halfway through, justify to yourself that you should take early profits or take a smaller loss.

My trading is very mathematical based now, on probabilities. So I know if I don't stick to 'the plan' then it throws the maths out the window and it's just gambling instead.