While I worked as a researcher at the Smithsonian Institution, I found sufficient conditions for happiness of my children. Through the words found at the Smithsonian such as "goals," "freedom and liberty," "history," "power and war" and "science," I want to tell my children about my ideas on things such as "dream," "difference and nature," "footprint," "beauty and love" and "God." This essay is about the relationship between dreams and happiness, difference between freedom and liberty, how to say if my children walk along my winding way, the individuals need to keep records of their footprints, the national need not to forget the past, why the bad power and war are always a step ahead of the truth, why Thomas Jefferson didn't describe himself as a scientist in his epitaph, women' beauty and love that can light the dark of terrible wars, the importance of scientific method such as experiments and observations during our children life, the importance of inner beauty as well as physical beauty, Why we believe in God, the importance of Love which is the one way to know God and humans, which is not hurrying and waiting for Mr. Right. I want to think about sufficient conditions of happiness with my readers.