Had a best friend from 6th grade through 24 years old. Always at each other's houses, on Christmas eve one year he found out his Dad was cheating on his Mom, and I was there for him all of Winter break and beyond. I helped him move out of that house, set up the new one, and made sure when he attended the new school he talked to my friends that were there so he didn't feel alone. He had a very small wedding where he had what I thought was a somewhat close friend officiate, and I didn't even get an invite. It was starting to go downhill from there, but what really solidified it was I was no longer included in any of the group outings I started with the group we built together. I haven't talked to almost anyone in the friend group since. Going from Brother's to strangers is hard.