I still have my Citizens Card which I only got for precisely the reason that Glastonbury wanted ID that year. It was cheaper than getting a passport iirc. Totally knackered and scuffed now and the hologram is almost non existent. Doubt it would pass muster these days.
Worst photo of me ever contender as I had a dental abscess and was totally miserable. Still obviously me though in date or not (don't think they expire actually).
All's well but have done nothing to get ready for G yet!