30 Lessons for Loving gives the relationship advice of hundreds of couples who have stayed together into old age, and will teach you how to have happiness and longevity in your love life.

If you've ever been in love, you'll know how difficult it is. At first, everything seems great, but once the novelty fades, the real work begins. Sometimes you just get a feeling that it's not right, and it doesn't even make it to that point.

So what does it take to find the right partner? And once you've done that, how do you keep your love alive for many years? There are a lot of books out there about the topic, but few have the power of personal experience on the matter.

That's why Karl Pillemer studied long-term marriages. Speaking with over 700 Americans who had been together for 30 years or more, he found the truth of what love really takes.