This question probably deserves more thought than I'm giving it, but -- I think my biggest regrets would have to do with (policy oriented) work projects I couldn't finish. And yes, in five years I could address those.
The same regrets that I have now - all the things that I didn't do. I'd like to think that, by being motivated by the absolute knowledge that my time is limited, I'd spend that time doing those things, but I suspect it would just be another five years to regret all the things I still didn't do.
I am having a hard time coming up with what I would regret. I am not by nature a regretful person, and I can't imagine that I would start upon notice of my impending death. If I was given five more years, I would probably continue doing what I am doing right now. I suppose that means I am pretty satisfied with my life as it currently stands, there isn't much I would change. If I could go back in time, I would spend more time hugging the people I have lost over the past few years. Five more years isn't going to bring back my dead.
Not managing to make it back to living closer to my family and spending more time with them. Trying to advance my career, get my MA, blah blah, has kept me at a long distance away. In the end I wonder how valuable that'll seem; if I got a 5 year reprieve, I don't think the plan would be different (first finish degree, then move) but it would be even more imperative.
Not writing my books. Not traveling more. Never having children. Not taking better care of myself. Not being kinder.
Not that I'm discontent. I'm very appreciative of all that I have -- my husband, my job, my mom, Jon's family, our health, the ability and means to take care of ourselves, with enough left over for a few perks.
Five years could go a long way. We're going to Alaska this summer, and thinking of Hawaii for next, then maybe Europe the year after. Maybe I'll actually start walking on my new treadmill (after I dust it). The books, well, that's up to me, too (a little more discipline, a little less exhaustion). As for children, at almost 48, I think that proverbial ship has sailed. Maybe someday we'll get a dog. And kindness is free.