1) You bounce back better from tougher problems.

From a study by Harvard happiness expert Daniel Gilbert, author of Stumbling on Happiness:

People rationalize divorces, demotions, and diseases, but not slow elevators and uninspired burgundies. The paradoxical consequence is that people may sometimes recover more quickly from truly distressing experiences than from slightly distressing ones (Aronson & Mills, 1958; Gerard & Mathewson, 1966; Zimbardo, 1966)… ["The Peculiar Longevity of Things not so Bad” from Psychological Science]

2) Regret is not that scary.

We anticipate regret will be much more painful than it actually is. Studies show we consistently overestimate how regret affects us.

Another one from Stumbling on Happiness author Daniel Gilbert.

…margins of loss can have an impact on emotional experience, and our studies merely suggest that however powerful that impact is, it is not as powerful as people anticipate. [Stumbling on Happiness]

really?  the regret i feel for not giving my dog more attention and affection in his final years has been tearing me apart since his sudden death a few months ago.  i have never felt regret like this.  it is much more intense than i expected.  :(

An excellent point. And a sad one.

You mentioned a special kind of regret -- one of the five regrets of the dying:

http://pandawhale.com/post/26909/top-five-regrets-of-the-dying

Specifically you're referring to #4: regret over not spending more time with loved ones. 

I believe that as a regret of the dying, it's got more impact than most regrets Daniel Gilbert describes. 

The impact specifically is to make us cherish relationships with our loved ones more going forward.

that is true. and it has had a great positive impact on the quality and quantity of playtime i have with my little sons!

it's never too soon to start enjoying the ones you love!

It's also a reminder to Be Here Now.

To not be consumed by the past. To not worry about the future.

But to appreciate what you have -- and who you have -- right now.

amen!

And appreciate what you are -- and who you are -- right now.

By the way, Daniel Gilbert has several good TED talks.

I especially like this one: "The Psychology of Your Future Self" ...