Rabbi Nachman taught that joy is a very valuable asset. When one is joyful, he naturally feels close to G-d. "Strength and Joy are in His place" (I Chronicles 16:27). One who is joyful naturally feels close to G-d. One who lacks joy inevitable will feel distant. He urged people to come to joy at all (permissible) costs, even joking and playing games. Once one is thus joyful, he can redirect that joy to joy in G-d, his Torah and Mitzvot. Although the Talmud urges us to be joyful by finding happiness in the Mitzvot (Simchah shel Mitzvah), he felt that nowadays few people are so spiritually attuned as to succeed in this, unless coming to the Mitzvot with an already joyous heart. He himself would sometimes go out into the street and play games with children in order to come to happiness.
A problem arises, however, if we seek joy through our accomplishments. Every human endeavor can be seen as lacking. Did I do it RIGHT? Was I perfectly sincere? Did I have ulterior motives? In one of his teachings, Rabbi Nachman urges giving ourselves the benefit of the doubt. This feeling of inadequacy is itself a trick of the Evil Inclination. if we give up on ourselves, we have lost the battle before we even started. In the final analysis, we did something good rather than something evil. We must rejoice in the spark of pure good in every action we have performed.
In another teaching, Rabbi Nachman grants that our actions are often not perfect. If one rejoices in one's accomplishments, one can always find something to be sad about. The remedy for this is to rejoice in what G-d has done! He made me who I am. He gave me life. He sustains me every moment. He brought me to a knowledge of Torah and the fulfillment of His holy commands that I might know Him.. In these things there can be no sadness. G-d's works are perfect! Happy are we that know of Him, when so many others are clueless! Be happy in our deeds? Yes, to the extent possible. But happiness in G-d's deeds is without blemish, readily available, and infinitely satisfying, meaningful, and joyful! Be happy!