Quote from Doug Allen:
I'm just curious about what other traders think is their biggest obstacle to success.
I know my biggest challenge used to be boredom and over-trading even when all my signals were telling me to stay on the sideline.
Maybe if we all share what our biggest obstacles and challenges are we could see a common pattern and then fix it! 
Doug
My biggest obstacle is: myself as a discretionary trader - I lost money, every month, every year, for twelve years.
Having somewhat sensed this problem, after failing repeatedly for a few years, since 2002, I've started working on building trading systems. And, in 2005, I've started working on automating systems, which is taking it one step further. I am sure many others have come to the same realization, sooner or later, but I am also sure only a part of them has carried through with developing trading systems and even fewer automated them. So I can say that, whereas I am my worst enemy (I still am - I lost 30% of my capital yesterday, because of my discretionary trading) as a discretionary trader, I am my best friend as a system developer. Very hard-working, dedicated, meticulous, persistent - I've kept at it for over 7 years now.
In the past year, my systems have made money pretty consistently, every month. At the same time, I managed to lose most of those gains because I was doing discretionary trading at the same time. So right now, even this weekend, I am struggling very hard against myself, to find a way to stop myself from trading discretionary for the rest of my life. I am trying to make sure I will never again click that "Transmit" button on the BUY or SELL order.
It usually happens when I get home and find some losses from the automated system, and try to make a quick trade to recover that loss. Usually it works. But my problem when it doesn't work is that I do not conceive using any stoplosses, so my loss can go on for days and can even blow out my account (it happened a few times already). I say "why shouldn't I be able to make some money by myself? I am better than the system I've built". Most of the time I can make money. Like 3 times out of 4. On that fourth time of my discretionary trading, I lose everything I made in the previous 3 times, plus much more. It's a total disaster. And I repeat this pattern since years and years.
Now, why do I think that I can simply recoup my system's losses by trading discretionary? Simple - who built those systems that make money? I did. So deep inside, despite repeatedly losing for 12 years, I can't believe that if I was able to build a system that makes money, I won't be able to make money by myself by picking trades. And yet, amazingly, each time I fail.
At this point, it's clear to me that I have limits there's things I am overlooking, and so I will try to physically block myself from even looking at markets, but I don't know if I will ever manage it. Yesterday's loss was huge and it's fresh now, so I won't try to trade discretionary for at least a few weeks. But then I'll get cocky again and little by little I'll get closer and closer to the trading platform, look at quotes... insert orders... click transmit eventually. I am very afraid it will happen again, and I am positive, after failing for 12 straight years, and 144 straight months, I am positive that I will not make any money, I will lose it instead, and I will never learn to trade discretionary. There would have to be someone there beating me up each time I don't use a stoploss. Or someone implementing it for me, automatically, but that is impossible.
So basically I do not know what to do. Part of the solution may be to implement such a great automated system that it will make money every day and then I may - maybe - get the point that it's best to let it run and not interfere, by second-guessing its trades, sometimes reversing them, and losing as a consequence.
It's awful... this month the system made about 100%, but I lost all of it in two instances: yesterday I lost 30% and a month ago I lost 50%. Each time I fall for it again. This year I blew out my account twice already. It's a total disaster.
On the other hand, as I said, thanks to being so bad at trading, I developed a great system. The big problem now is letting it run, without thinking that since I am the creator I must be better than it is. Seriously, I do think deep inside that I am better than the system at picking entries. Then I see that it entered a position - I think it's wrong (I did friday), and I'll reverse it. At the end of the day I lost, whereas it would have made money if I had let it work.
It's a total disaster... I have the worst psychological make-up for a trader. And I don't fully understand why yet, or else I wouldn't be like this. Maybe I am self-sabotaging myself or maybe I really think it will work - but it's a fact that I failed at it for 12 straight years.