Regret vs Ponderance, which camp are you in?

So I have a married friend that is in a strange head space with Ken and he with her. I say this because she is married, has kids, and all that comes with that. So the comments are always about her next life. This leaves me wondering what that means because I have "in my next life" thoughts too about a great many things. Does this mean that we will be willing to make changes after our kids have left home, when we are widowed, or truly in the next life we lead? Is it fair for us (and I am talking about us as people in general) to stay the course out of responsibility rather than to follow our hearts? The question my friend asks is how do we live with the decisions we made in our early 20's for the rest of our lives? I am not sure this is regret as much as it is ponderance.