What's a 'first time' you'd love to experience all over again?

A first time id love to experience again is my full relationship with my ex. When we met, i personally knew i would love her. We were complete strangers but the way i made her laugh, it was such a genuine laugh that you can't just tell no one else makes them laugh the way you just did. The warm aura the radiated from her presence. I didn't know her at all, yet everything about her felt so special. then once we had been friends for a while i remember we really did start getting really flirty and kinda just being silly knowing each other liked each other but not explicitly saying it or acting apon it. one day, a week before cristmas i vaguely asked if the feelings were mutual. I did get confirmation, just as vague back. And i remember just like it was a few minutes ago just how engulfed in butterflies i was. everything inside of me was embarrassed and also so excited, I'd never been so vulnerable and felt so safe with someone. That's when our first I love you happened, i remember just like it just happened. or relationship was so great I've never felt like i could ever live a different person the same way. and this is where i think of like it to cut off or loop or go a different direction. but it all started getting more and more bitter feeling. i felt as though she was becomeing more and more distant and trying to purposefully avoid me, while i keep trying to not get it in my head not just accept that it was just to good to be true. I wanted to believe it was still salvagable. But i ended up becomeing really passive aggressive over it and i kept subconsciously being rude and/or inappropriate to her and that ultimately ruined what little bit of relationship we still had left. and im not sure there needs to be anything more to the story. i will say that honestly looking back, im not sure that we even should've been together but that's about it.