Lessons learned from successful investors:
First: If you do not have even a small amount of anxiety over your investments, this means that you are not risking enough. You have to have enough money invested in order for you to have real interest. You will make the right decision when you participate in your investments with all your feelings, and then you will be able to monitor this investment and give it greater care.
I am not so sure about this lesson.
Personally, I'd say study with great care what you are about to invest into, and when you finally make the investment, start small. Do not start with an amount that, if lost, you will lose several nights' sleep over it.
I'd say further that interest comes way before you even start pulling out money from your pocket.
I also do not agree completely with the lesson, it is true that if you are not anxious about the money that you are investing or trading in the market most probably you are not risking enough money, that is true, but I do not see how that is a bad thing, I say this because most people have a strategy that if followed correctly it will make them money, however when they fail it is because they let their emotions take control of their trades.
They either get too greedy or too fearful to follow their strategy and as if on cue the market will move in the opposite direction they were expecting and they will lose a massive amount of money, so it is important to always be in control of your emotions and if your emotions become unmanageable then you need to reduce the amount of money that you are risking.