I think you are right. It's all about confidence. The more confident you are the more money you will make in the market. The tricky part is that the confidence is created forwards not backwards Eventhough you underperformed your own system I think this is quite normal. You didn't have enough confidence to trade it. Confidence needs time to build. With the time you will get more and more confident in yourself and you will get better and better results. Just keep the risk under control and you could be as rich as you want
Here is an experienced trader and manager asking you to simply demonstrate your expertise before he invests money in you...a very reasonable request...and you call him a blowhard? Is this how you handle all your job interviews? Like an ass? As a new trader with all of 30 days under your belt, you should be thankful for any advice or guidance, not insulting to those who provide it.