Is there someone you miss so much and you cannot get them out of your head?

For me it is my ex boyfriend. I know he is happy as he got engaged to a nice woman two years ago and I assume they married soon after. I want him to be happy but I miss and love him so much. There is nothing I can do though except let him live his life without interference from me. Sometimes loving someone means letting them go as that is what is best for them. I hope he found what he was looking for. I broke up with him three years ago because of my personal problems and not wanting to make him wait forever for me to get my life together. I will always love him though. He will be in my heart for forevermore. The love that remains in the heart and cherished memories keep the love alive.