My closest friends and I had such a blast playing through the game when it first came out, we didn't have fun like this since our teenage days.
We all felt immense nostalgia and it reminded us how much fun we used to have. We talked like before, we connected like before.
When we finished up to Yagluth and had nothing else to explore for, one by one we stopped playing, and went back to the "reality". Sure, the full release would've been the same but with the end, delayed by more hours. But that would've been so precious, those extra few hours we would've gone through together for more.
When the Frost Caves released, some of us returned and played together again, and there was nothing like it, yet again.
I ended up being the guy who kept building, maintaining bases, filling up the containers with food for when my friends to return. This is such an odd feeling and behavior for me, cause I socialize A LOT, like, I have 4 different groups for each hobby in my life, with at least 10 people per group, so I don't really need to "fill my social needs" to not feel alone, but there really isn't anything like bonding with your childhood friends who are now busy with just.. being adults, taking care of families, paying bills.
Valheim made us remember the days we just had fun as tiny humans, and I wish this could've last much longer in one go, but, it is what it is. At least we had a glimpse to bond again, and I think it got us all closer again.
Source: https://www.reddit.com/r/valheim/comments/t9uvcj/sometimes_i_wish_i_didnt_know_about_valheim_until/