The act of service cannot be overemphasized. Most of your success in life will come from the place of service.
People usually put in more work to what they fell will benefit them and give in less effort to what doesn't reward them. Life does not always turn out the way you expect, people would not always reward you when they see you are only working for your selfish gains all the time.
It is said that the greatest thing in life would always come from places you never expected, what you do not work for or deserve. Even in your work place, the promotion you get comes from the selfless service and value you put in the organization that you worked for, when you don't think about yourself only that things eventually turn around for you.
Give out selfless value.
Don't take yourself too serious, wherever you find yourself give out value with out thinking of returns, serve people, be useful and give in your all, and the reward would always come naturally. Be willing to serve and don't put your mind in the expectancy of reward for your work, because at the right time and with the right people you definitely get what you deserve.
Success should not be tied to what you receive only, but by how well you are willing to give without asking back for return. When your priority is to add value to others, there is this thing called life that usually gives you what you truly deserve at the end.
Give value, be selfless to the point that people are forced to give you back to you by their own will.