1: It implies that you may be embarrassed because you can't keep your promise easily.
2. Suggest that holding a huge sum of money will make you happy all your life.
3. It means that your social status will be improved, and you will no longer be at the bottom, and the money that comes with it will make you very satisfied.
4. Explain that you have no confidence in yourself, or are dissatisfied with your current job and want to change jobs, but you are hesitant.
It means that in order to overcome the difficulties, you will have a tiring struggle, and only after the struggle will you feel that the difficulties are far beyond your imagination in advance.