That's exactly it. I miss the beautiful lie that never truly existed.
I lamented my big ex for a years who left me for someone with money. Oddly it was a Wes Anderson film, The Life Aquatic with Steve Zissou, that broke my fever.
He had a submarine on his ship that was once called Jacqueline but the name was crossed out. At some point his new found son asked who Jacqueline was, and Steve says the damndest thing:
"She didn't really love me"
That was the important bit missing in my heart. There wasn't something that had been truly lost, it was never there to begin with. The person I thought I loved was a mirage and a facade. I'm sure for some that would make it worse, but it helped me greatly.