My ex-wife was a very outgoing woman, but after our divorce was final, it was almost like she dropped off the face of the earth. We exchanged a few emails maybe 5-6 years later. A year or so later, I saw her coming out of a Dunkin Donuts while I was in the drive thru lane, so I looked her up online and found out she was getting married again in 2008. But, I never contacted her and haven't heard from her since.
During the divorce process, we kept in touch regularly, but nothing like what you experienced.