Great article on the general concept that people are very bad at predicting what will and will not make them happy.
[link=http://query.nytimes.com/gst/fullpage.html?sec=health&res=9E0DEFD61538F934A3575AC0A9659C8B63]Article[/link]
It's a really long read but still provides great insightful into human happiness. In general, the studies in the article have shown that "we falter when it comes to imagining how we will feel about something in the future."
"And whether Gilbert's subjects were trying to predict how they would feel in the future about a plate of spaghetti with meat sauce, the defeat of a preferred political candidate or romantic rejection seemed not to matter. On average, bad events proved less intense and more transient than test participants predicted. Good events proved less intense and briefer as well."
Hooking that hottie at the end of the bar isn't going to be as great or provide you with as much positive energy as you might think...BUT, conversely, being rejected by her will prove to be much more fleeting and more innocuous than you might have predicted.