What binds us to the past? Nothing can, but we believe we are bound to it by the power we give to regrets, guilt, self judgment, unforgiveness, anger, shame, etc. There is a difference between being in the present moment and remembering a past experience versus living in the past. In the former you remember, you re-experience, the feeling of joy and love from an experience such as your marriage or the birth of a child. Although this happened in the "past", you are bringing it to the present moment, which is all that exists, through the vehicle of those attributes you inherited from God --- joy, peace, and love. In the latter, you are not living in the present moment, because the power you give to regret (just one example) binds you to no mans land. The past does not really exist, so you are not there, but neither are you in the present moment, because in this one moment, nothing false exists (regrets, guilt, etc).
If we have regrets, we are saying more than the fact that we wish we could have done it differently. We are beating ourselves up (guilt, self judgment, unforgiveness --- all legs on the same stool), and not allowing ourselves to experience the wonder, joy, and peace that comes from the present moment. Now, you can say that you wish you had done something differently but be in the present moment. We all have things that we would have liked to have done differently, but we can choose how we look at these "regrets", and we can choose whether we judge ourselves.
How do we take a "negative" experience that happened in the past and let it go? We think differently about what happened. For instance, if you had something traumatic happen in your childhood, you now have the benefit of a much wiser perspective as an adult. What that little boy or girl thought at the time the experience happened is very understandable, but you are now an adult, and it is likely that your resources to heal from that experience are completely different. By staying in the present moment and bringing that experience into that moment, you can transform it. We heal things by bringing them to the present moment. That is where He is, and when we come to the present moment, we are acknowledging who we are and our innate ability to heal ourselves.