I don't know how I'm going to put all my feelings into words that form correct phrases but I'll try.
First of all, this is Adam Silvera. Get your tissues out from the very start.

To be honest at first I found the story weird because I was pretty sure it was going in a certain direction that didn't feel right to me. But I actually really liked how it planned out and all the weirdness I could have felt throughout the book was swept away.

What I loved most was how truthful it was.
I don't know much about grief, or even about love, but this story felt so openly real that I got sooo emotionnaly envolved.
The characters are flawed - especially Griffin, and his actions are not all good. But, like a puzzle that gets easier to make after a few mistakes, life is a learning curve.

I also liked that, it wasn't just about love, but also about friendship and family. All the kids' parents had their place in the story and weren't left out. Seeing all of them interact was beautiful.
I will not even try and explain how I felt whenever Theo's parents and sister were around because I will only end up transforming my room into a pool of tears.

Just... Ugh. It was really good.