I assume you're talking about the tattoo? I took it more in the sense of a reminder and motivator for what he needs/wants to do, as well as a sign of regret for times he couldn't save or help Presepe. I didn't take it as (unhealthy) lingering attachments, but as a way of letting go of his despair - while he moves on, the tattoo stays there to remind him what has happened and that it can happen again. He's taking his sorrow, anger, and desperation, turning them into something to strenghten his resolve.
If that sounds confusing, think of it similarly to "forgive but don't forget" - you let go of your emotions regarding it but that doesn't mean you forget, and it may not mean it doesn't still hurt sometimes, but the hardest parts are gone.
But welp, this is just my interpretation of that ╮(￣▽￣)╭
Why should you make yourself remember every painful memory? Seeing someone torture themself like that doesn't seem like self love...aka a red flag for me