Is this ADHD or some coping mechanism?

It applies to both traumatic events and happy events.

It becomes just another thing I've done and I soon "forget" about it.

If you ask me what my happiest or saddest moment in life was, I don't have one. I can judge the things that happened to me objectively and say they were happy or sad, but in my memories they don't stand out... emotionally?

Do other people also feel like this but they just don't care so much about the distinction? To me, if something doesn't trigger strong feelings in the present then it feels like it doesn't matter so much.

I always say I don't miss people, because even though I think about them and it would be nice to see them, their absence doesn't hurt me.

After a breakup, I pretty much forget most details of the relationship, as I'm not interested to reminisce anymore and "renew" the memories. It's like I barely knew the person, even though when we were together my feelings were very strong.

I used to heavily minimize bad things that happened to me. It was quite difficult to process that they were such traumatic events once I became aware of it.