Summary of Reddit comments on "how to forget an ex":

Advice on Moving on:

Time: "The memories will always be there, but hopefully they'll start to hurt less over Time."
Focus on self: "Concentrate on things you like...take Time for yourself and concentrate on things you like."
Pick up a new hobby: "Quality Time spent with yourself doing something you enjoy...can heal many wounds."
Find someone new: "Find another girlfriend who treats you better than the last."
Therapy: "You need to see a therapist and get to the bottom of your inability to let go."
Change environment: "If you remove all the reminders of them it will become easier to forget."

Avoid dwelling on ex: "Get busy doing other things...stay busy."
Don't mention ex: "Don't mention your ex. Just... don't do that."
Avoid stalking social media: "Don't stalk her social media. Hide or get rid of mementos, pictures, and reminders."

Stay occupied: "Get out and meet new people."
Self-improvement: "Go to the gym a lot...makes you feel really good about yourself."
Forgiveness: "Forgive her."
Cord cutting spell: "Cord cutting spell can also help...seriously, Therapy."
Maintain distance: "Cut contact as much as you can...it will eventually get easier."

Various comments jokingly respond to a scenario involving spiders and abuse accusations.
Some users provide comic relief and anecdotes that add a light-hearted touch to the discussion.

Time, self-reflection, new hobbies, Therapy, and avoiding reminders of the ex are highlighted as effective ways to move on.
Prioritizing Self-improvement, social engagement, and avoiding unhealthy habits like stalking or dwelling on the past are also recommended strategies.