Unfinished business

See, there's this book (http://www.amazon.com/Unfinished-Business-Extraordinary-Trying-Things/dp/1596916753/ref=sr_1_1?ie=UTF8&s=books&qid=1277750537&sr=8-1.) The long and short of it is that we all have unfinished business, and it likely compiles every day. I know that I, personally, don't have nearly enough days that I just live the crap out of.
Now, mind you, that I haven't even read this particular book yet. But it's such that I know I'm going to love it, just based on the idea of it. I love that someone thought about it and took the time to go back and finish some of his unfinished business. To thank people who have gone unthanked. To return library books and visit places and see sites.
Thinking about this, in terms of myself, leaves me daunted. I see my life as a minefield of opportunities wasted, regrets, lost friends. In fact, thinking about my unfinished business is not quite inspiring. So where do I go from here? Do I quit my job and make it my life's work to go back and revise all of the missed chances? Do I settle on just starting to leave no business unfinished from here on out?
At least I have no old library books to return.