Let me share some of the best advice I have ever received.
I never met the French scientist Louis Pasteur, but when I began my adventure as a missionary, the following words by him were repeated to me until I could never forget them. "Let me tell you," he said, "the secret that has led me to my goal: my strength lies solely in my tenacity."
Tenacity: the quality of holding fast; of being characterized by keeping a firm grip; of being persistent.
This phrase embodies a lot of wisdom, but one thing that it taught me is that my duty trumps my desire. Sometimes, I would prefer not to do hard things; I don't have the desire; my circumstances don't make it easy. There are always a miriad of excuses, but duty is something that cannot be excused.
I believe it might be a duty to be happy; to search for knowledge and beauty and find peace.
True, it is a difficult duty at times--we are like water and seek for the path of least resistence--but we can rise above our circumstances; we can choose to shape our own destinies. We can choose to be tenacious, for therein lies our strength. If I am only good when it is easy to be good, if I only forgive those who forgive me, if I am only happy on days that are 75 degrees and sunny, am I truly good, forgiving or happy?
In others' words...
"If men had postponed the search for knowledge and beauty until they were secure, the search would never have begun....Life has never been normal....Humanity...wanted knowledge and beauty now, and would not wait for the suitable moment that never comes....The insects have taken a different line: they have sought first the material welfare and the security of the hive, and presumably they have their reward. Men are different. They propound mathematical theorems in beleaguered cities, conduct metaphysical arguments in condemned cells, make jokes on scaffolds, discuss the last new poem while advancing to the walls of Quebec, and comb their hair at Thermopylae. This is not panache; it is our nature."
- C. S. Lewis