They are some of the most familiar but most beguiling questions of people's lives: Why do we fall in love? Why do we fall out of love? Why do people feel so deeply the desire to start a family?
"Nightline" explored these questions and more in 2006 -- everything from what it's like when guys take classes in how to pick up girls (the teachers insist they're teaching sensitivity), to how you can still get a quickie wedding in Las Vegas (better go before midnight).
For many people, the desire to love and be loved by a child is so profound that they will struggle through a myriad of heartbreaks and enormous expense to achieve it.
We spoke to young women who chose to freeze their eggs now so they will be viable for years to come; to couples who tried over and over again to have children and finally turned to in vitro fertilization; and to women who came to the same conclusion, though they were not married -- single mothers by choice.
"Nightline" followed several young couples who had succeeded in bringing a child into the world, only to watch with love and desperation as their babies struggled to survive. Doctors used latest technologies in neonatal intensive care units to try to save babies who, just a few years ago, would have had almost no chance of survival.
Montreal researchers searching for a tanning aid discovered an interesting side effect, and in the process, may have discovered the Holy Grail: a medication specifically targeting lack of desire in women. And as pharmaceuticals have helped older people re-ignite hibernating libidos, a new problem has emerged in an unlikely demographic. Senior citizens are facing rising rates of sexually transmitted diseases, and "Nightline" explored the challenges of teaching safe sex to the social security set.
In 2006, Suri Cruise and Shiloh Nouvel Jolie-Pitt were born, and it was the year the Supreme Court ruled in favor of Anna Nicole Smith in her fight for her share of her ex-husband's billions, setting a possible precedent for probate law.
Among celebrity couples, Whitney Houston and Bobby Brown called it quits this year, as did Britney Spears and Kevin Federline. But perhaps no split caused as big a stir as Paul McCartney and Heather Mills. The Beatle's breakup raged in the headlines and the ensuing legal battle pitched a former model against a very powerful, very popular man.
Far from the headlines, "Nightline" also explored the more minute concerns of loves unrequited or broken by the end of a life.
We spent time with a brilliant young piano player who had lost some of his focus because, he said, he was in love. The young man is autistic -- he has trouble with even the most basic social interactions, so what is his experience of love?
We also sat down for a candid conversation with author Joan Didion, whose book, "The Year of Magical Thinking" recounted her life following the death of her husband, John. The two lived and worked together for 40 years and were as close as humanly possible. Their love and separation, and her reflections on both, are profoundly affecting.