That's right! Be contented as long as you can earn which you think is enough. Being greedy is not good and mostly it turned to a huge loses. Be a wise investor is the best thing we can do and not aiming so high. Just find a good project to invest which you think you can make profit that satisfy you.
Yes, greed is not good for anyone to use and in any case because greed will not bring success to anyone in any work, so I strongly agree that everyone should always be wise in carrying out their work.