Why did you give up your Mechanical Engineering studies so easily? Fluid Mechanics in 2nd or 3rd year would help you in trading big time. Engineers only need a touch of psychology study and they're ready to fly as traders. Seen a thing or two in this regard.
I don't know what role Ego plays in trading, but it has to be taken seriously. Emotions can become your enemy in this case. As in any other business. Therefore, in any situation it is important to stay cool headed and purposeful. I would say that you don't need to try to get everything at once with the help of trading. No one has ever managed to start earning a large percentage in two weeks. Don't be too confident. You have to learn all the time, find new information. Time does not stand still. You need to keep up with it. I would add that trading loves those who are ready to develop and get new skills.
I think that you mean egoism and greed not as phenomenon, but the problem is more global. People are overconfident and think that they may earn more. Yes, that's greed, but not egoism. People don't know their strength well and don't have enoigh self-control to stop trading and take profit when it's hight. That's all about over-self-confidence. And really, a lot of people are overconfident and become thrill in trading. And I don't have any solution to this. I think every trader should experience losse caused by overconfidence and than make a decision. That's only way to overcome greed. Of course, people can learn to control themselves, but fairly, that doesn't work so.