Decide, first and foremost, that they need to be forgotten. Realize what a profound statement it is to make towards another person that they need to be erased from your life, that their very presence in your mind is causing you to suffer and to needlessly agonize. Understand now why, for so many years, whenever a friend or a more insignificant lover would rub you the wrong way or do something you felt was cruel and unnecessary, you found a more amicable way to deal with them than to cut them out completely. Begin to visualize your web of friends, of family, of social contacts, as something inherently interconnected — understand that to remove someone entirely is akin to breaking a chain which everyone expects you to keep together. Anticipate awkward run-ins at parties.
Know that, regardless of the social repercussions or the initial difficulty in adjusting, removing them (at least temporarily) is essential. Try to imagine being able to expunge their ghost from your life while still constantly seeing them, and understand that it is impossible. Their presence has become nothing more than salt in the wound that you have realized is more open than you had anticipated. Every time you see them, you are overwhelmed with a simultaneous desire to flee and to run into their arms, and you know that neither of these options are acceptable. Come to terms with the difficulty of cutting them out, and begin on planning how to do it.
Erase them from social media. Erase them from your phone. Erase your old messages that you have a tendency to go back and read as much out of masochism as nostalgia. Have a profoundly difficult time making each conscious step towards erasure, but know that they are needed. Even existing on the periphery of your life would be too much for you, as any contact with them or access to their life only serves to torture you with what could have been and what will never be. Know that you cannot suppress your natural instinct to click on their page or send them a drunken message at 3 AM, so prevent yourself preemptively from doing so. Know that this may mean that news, such as them finding an eventual new love, will be even more of an unpleasant surprise — but hope that it happens in enough time for you to begin to heal.
Actively make lists in your mind of all the things you didn’t like about them when you were together. Force yourself to remember the fights, the inherent disagreements, the dragged-out silences which grew more irregularly punctuated with good times. Make “this ended for a reason” your new mantra, even if the words ring as false as a guidance counselor’s motivational poster at first. Draw a map of all of the places you do not want to return to in your next love, and all of the things about them that you were only so eager to change when they were still in your life. Focus on the flaws, the downsides, the insults, and the part of you which knows on a more cerebral level that this is all for the best.
Fill your time with tedious-but-distracting activities which permit you to forget about the inner monologue which won’t stop churning in your mind and filling your ears. Go out, meet people, start a new hobby, get into a new show, force yourself to be at least a facsimile of an active person — do this until you start to feel yourself become one. Rely less and less on the distraction factor to motivate yourself to, say, clean your entire apartment from top to bottom. Note each time you extract joy from something that does not stem from the person you’re forgetting. Recreate such joy in every way you can, being generous with yourself and allowing you to be the spoiled child who needs attention to heal its wounds.
Write about everything. Imagine every emotion you’ve kept in you for the past few months — from the moment you sensed it was ending to the moment you needed to expunge this person from your life if you were to ever move on — as a ball of yarn in the center of your chest. Allow yourself to slowly unwind it with every word you write, not worrying about how cliché or self-indulgent your sentiments are. Don’t worry if the writing is good, only that it is honest and gives an accurate portrait of the person you have become of late. Read it over and over, look for clues that you are giving yourself that you almost refuse to consider consciously. Look at your words as though you were a stranger, and try to see the mistakes that you’re actively making.
Begin to feel yourself repair in a way only marked by growing apathy. Realize that such apathy, this lack of consideration for the person who used to dominate every waking thought, is the true opposite of love. Laugh at your clumsy attempts in the first crushing days after the separation to mask your unrequited longing with a kind of pretend hatred. Realize that you never hated this person, only resented them for not reciprocating your desperation. Understand, though, that “forgetting” was never the real intention, even if it’s what you needed to say to get yourself on the path of recovering. See that “forgetting” is not something we can ever strive for as humans, but rather a sense of “accepting.” Start to realize that, on your horizon, there is a point at which you are fully independent from the pressing thoughts of a former love. Walk towards it with conviction, and know that one day all of this will seem a distant memory.