Leave the past behind?

I'm happy with the person that I'm developing into and truly grateful for all the events that surrounded my life since starting university. Yet there's a tiny part that wishes I could somehow return and reunite with my past. Trying to see if it is possible to somehow merge the past and the present altogether. I'm not even sure if it is something I truly desire or if it serves to rectify whatever mistakes I made in the past.
 
The thought keeps occuring periodically and it is frustrating. I don't get it. The path that I'm on has given me so much and I accepted the fact that people come and go in your life and whom they were in your past is very much a part of who you were and become in both the good and the bad. So knowing all this, why is there still a part of me that wants to come back?
 
Perhaps, It's finally time for me to bury all those mistakes of the past, cause I've finally learned the lesson.  Accept the fact that the way things are they are meant to be even if I don't like it and just move on. I just wonder how much I have to leave behind. Maybe I'm just a little saddened by the reality of it all even though I know in the long run it is for the better.