Chocolate has the effect of happiness on most people as it releases endomorphins from the brain.
Also, "Chocolate contains a pair of compounds known as phenylethylamine and serotonin, both of which affect the pleasure centers of the human brain. Likewise, the cocoa bean produced by the Theobroma cacao tree is considered by many as a "super fruit" based on its "antioxidant capacity and content of naturally occurring compounds such as polyphenols within those whole fruits or juices of the fruit which may be linked to potential health benefits," as cited in a recent report study with the Chemistry Central Journal"
Yes, really Dark Chocolate works. It gives the same feeling as being in love with someone, making you "happy".