
One of my favorite idioms in English is "burn your bridges", meaning to do something with the result that you will not be able to return to a previous situation again, even if you want to . Sometimes it is imperious to do it in order to let go of the past and move forward, less burdened and more confident.
Still, before thinking that everything is "water under the bridge" (what happened in the past should be forgotten), you should take all precautions in order to leave all worries behind while "crossing that bridge when you come to it", since you do not want to take bad memories with you on the other side...