It's pretty simple, out of site is out of mind. For me it all boiled down to getting rid of just about everything my ex owned and everything that reminded me of her. You see time heals all wounds and sooner or later you'll get over your ex, but it's harder to do that when you have things that are constantly reminding you of them.
I deleted all our pictures together so that I don't end up scrolling through my phone and feeling depressed at the site of our pictures. It was really helpful because I never had anything around me that reminded me of her at all.
Finally I made myself very busy. I decided to focus all my energy on bettering myself, I took professional courses, worked out more and just kept myself so occupied that I never thought about her for a single second. At the end of the day, I'd be too tired to even stay awake long enough to remember her.
When I finally did remember her, so much time had passed that I guess the wound she left didn't hurt as much.
I hope this helps.
It's simple. Get a new boyfriend or girlfriend. Buy some bitcoin and monitor the highly volatile prices. Soon, you'll forget everything about your ex.
Smoke a lot of marijuana and you will automatically forget things