There are many things which are possible, looking at the supreme power of Allah Ta‘ala, but are not normally achievable, e.g. A man at the age of 95 who has a host of health complications is anxious to come out first in a marathon. The secret behind a happy life is in not going behind these things, since it would bring endless discomfort to us and others.
When trying to achieve something, never project a figure. This projecting brings about two problems, (1) You will become despondent and very soon fall into a depression, and (2) Out of frustration you will begin to fight with everyone. The state of the mind should rather be: “I will work and then be happy with whatever I receive. If I do not receive enough, tomorrow is another day. I will try again.” In this way you as well as those around you will remain happy. But when you project too much then initially you will hurt yourself and with time you will want that hurt to fall on others as well. You then get gripped with jealousy and begin to run others down etc.