Balance that never happens

Have you ever thought if we could travel time, what could have possibly done by this time? There are certain things in our life that always bugs us inside but we can do nothing about them. How much peace could we possibly have gleaned, if only time traveling can happen for real? Needless to say, how many of us will live gratifying lives in different timelines for the decisions we took and for the amendments we did. 

UPDATE: I watched "Dark" now I am in sorta denial.