The past is the past, no sense in regretting it since you cannot change it.

I'm not quite as old you but close, and I already feel what you're feeling about the time left. That there isn't a lot of it, or that it will be gone quickly. Everyone has things they will not get a chance to try or experience. No lifetime offers everything, and every path taken means many, many others will be never explored.

Like money, you can't take memories with you. So try not to dwell on things you didn't do or that didn't work out the way you imagined. Half or more of people who get married end up divorced. Probably many more are less than happy. Kids can be a joy but they can also be a heartache. Every criminal is somebody's kid. Nothing comes with any guarantees.

Make life interesting today, as today is the only thing you really experience.