Speaking of 100+ year old standards <sic> ... ask a photography friend who advocates Full Frame DSLRs why they think Full Frame is the holy grail of photography. Hilarity shall ensue.
There's two things I love about 35mm - first, along with most numbers used in photography, it shows Americans can cope with (and indeed embrace) metric, and second the origin is a 'let's get 16 frames to the foot of motion picture film' arbitrary decision made in the late 1800's.
That it defines so many amateur photographers' desires 130 years later is perversely delightful.