Is this a common thing?

ok so at my gym there are several changing cubicles with doors or there is a bench area to get changed .. there is also lots of showers with doors and some without but no one uses the changing or shower cubicles with the doors and they just walk around but naked the other day i saw an 80 year old in a thong and nothing else .. i always use the cubicles and showers with the doors but no one else seems to .. why? .. does this happen where you live? .. and where about do you live .. me England