Have you ever lost a friendship you thought would last?

I was actually having this conversation with a friend today about some of the online friends I've had. A lot of them I lost because I outgrew them and realised how toxic they were. Someone in their 40's has no business being friends with an 18 year old anyway, that's weird and did more damage than I even noticed at the time. The others were just a matter of growing up to be a different person with different boundaries. That's normal.