I've been in your situation many times, and one of the most important things that I've learned about moving on from a person/event is that it takes time, effort and energy before you are able to finally let go and move on. There's no quick and easy way to get over something or someone, especially if they have or had emotional significance in your life.
When you just try to forget them; when you try to run from the memories without analyzing, understanding, or reaching a state of enlightenment about it - I don't think you're able to truly get past it... Unfortunately for some people, they never do this inner work, which does require pain, introspection and reflection, and as result they just keep trying to distract themselves (which is exhausting and ultimately harmful in the long run) and aren't able to fully recover and heal from past relationships or from the experiences in their past.
The fact that this person keeps coming up in your consciousness can be taken as an indication that there are still unresolved issues that you have with them. For me, I needed to process what had happened between us and to find what lessons I could learn from it before I was able to finally reach a state of peace and acceptance- with myself, with my actions, and with them and their actions - and move on.
I believe that every experience and relationship can be learned from. Where there is pain and hurt - there is the opportunity for enlightenment, healing and growth... and so these people have helped me to develop skills in love, understanding, compassion and forgiveness. I had precious realizations while writing and working out my thoughts and feelings about the people I had/have relationships with (e.g. about myself, about others, and about what I needed and deserved in relationships), which I am very grateful for, and it has helped shape who I am today and what it is I value.
I've also been lucky to read quite a few spiritual and self-development books and blogs, the wisdom of which has helped me immensely in my journey. If you're interested in reading some of those top materials, I would highly recommend the books "
Women Who Run with the Wolves," by Clarissa Pinkola Estes, "
A New Earth" by Eckhart Tolle, and "
Way of the Peaceful Warrior" by Dan Millman.
I hope that this post was able to help you in some way (and perhaps others), and I wish you well on your journey. <3