The more we wonder about the "whys / what ifs" when it comes to our past - the more likely we are to do a quick u-turn and find ourselves in the same situation as if in a time loop.
In order to avoid doing so - we must make a conscious choice to keep moving forward and not be dragged back into the past.
I apply this thought process to pretty much everything I do - even when it comes to personal relationships with people. If I don't think someone is right for me overall - I let go and just move forward. I don't spend too much time dwelling because there's no point in it.
If something isn't working out for you - regardless of the situation i.e. work / personal life / education etc chalk out your options / alternatives and strive forward. Once you've made that choice - don't dwell on the past. This is when applying the 3 C's of Life will help you : make a choice to take a chance to change your life !
How do you stop yourself from looking back ? How do you stay focused on the future and not linger on the past ?