How does an avoidant move on so fast

Avoidants turn off emotions like that so they don't experience them... they have been conditioned to do this from an earlier age in life and it got even more prevalent in their life as things with people might have not worked out for them. I'm yet to meet an avoidant whom has never gotten help that has actually been content with themselves and their relationship even with secure partners. It's not because they are bad people but having that avoidant tendency does that to a person. They aren't heartless and they aren't emotionless, they just have conditioned themselves to not attach to avoid being hurt. I always say they are like a walking coping mechanism that is always prepared for the threat of closeness. You need to realize that history will likely repeat itself with whomever he's with. There was this fascinating study that I wish I still had the link to that older adults that never get married or have kids are likely to be borderline/narcissist or have avoidant attachment... these people made up a significant chunk of that unmarried group without kids. Also they are way more likely to get discovered multiple times.