Properly worn out, to the point of retirement....
2 for me,
1- Columbus jazz that I took the frets out, and ground the neck and pick up covers away. Not worth doing up or selling so it was retired.
2 - fender precision light special edition. Many many gigs. Played so much that I ground the mahogany body away around the pick ups, and the pickups rattle loose after a short amount of time playing. Frets played smooth. Gone thru a number of jack barrels too. Too much sentimental value to sell. Too knackered to gig!!!
(Still the best neck I ever played)