How To Forget Someone

Do not talk about them
This is the first way to forget someone and the easiest method too. If you do not want to remember something, then the best course of action is to avoid talking about it. . Talk about anything else instead!
Don't go back to places where they were last seen
If you live near where someone was last seen, take time out and don't go back. Chances are that your memory of what happened is going to fade over time, and if you end up recalling memories of the person, chances are it won't feel real anymore. Go somewhere else, eat lunch at a different place, or just get on with your day.
Change things around you
Another way to forget someone would be changing the subject. By doing this you stop thinking about them altogether, and this is a great way to move on. It's hard though, especially when you know what they said before, how they looked, or what they did. Just make sure you change topics and focus on something else.