Today marks the 90th anniversary of the first broadcast by the BBC; not, in 1922, a crisis-wracked 'Corporation' but instead the very commercially-minded British Broadcasting Company.
Beeb 1.0 was set up by a syndicate of radio manufacturers to give early-adopter gadget-crazy punters something to listen to with their shiny new wireless sets, cool devices which were the iPhone 5 of the early 1920s.
When I tell trainees that they're usually gobsmacked.
They're so tramlined by the meeja studies orthodoxy to think in terms of 'public service good - commercial profit bad' that they find the very idea of a commercially-motivated BBC somehow awkward and disturbing; a bit like finding a faded Polaroid of your respectable auntie propping up the bar in fishnets and stilettos.
They're also amazed that radio is so young; the entire history of our medium, from 2LO to Absolute 00s, from Arthur Burrows' first news bulletin to Grimmy's more music breakfast show has happened well within the lifespan of one of today's sprightly Saga-holidaying pensioners.
Undergraduates typically think radio started about the time of Napoleon; our medium is such a part of everyday life, like electricity and running water, and the technology of receiving it so simple that they just can't imagine a time without it.
So let's take a moment at 5.33 today to celebrate the achievements of all radio.
The BBC pioneers who set the standards, steering the Corporation through a general strike and a world war without becoming a propaganda service; the anti-establishment pirates who introduced much-needed populism and choice for listeners; the local radio pathfinders, led by Frank Gillard, who brought radio into communities; and their restless commercial counterparts who have through necessity found new and innovative ways of engaging with audiences.
Lest we succumb to the temptations of declaring the past a never-to-be-repeated golden age, lets's also celebrate today's innovators bringing radio to new platforms and new audiences.
Stations like FunKids and The Wireless at opposite ends of the DAB age spectrum, Jazz FM and Planet Rock carving out specialist musical niches, Absolute Radio segmenting markets into smaller demographic slices whilst Heart consolidates disparate city stations into a larger, homogeneous whole.
Some of these experiments (and cross-fertilized BBC/commercial innovations like the UK Radioplayer) will succeed; others will be doomed to failure. Evolution is driven by experimentation; the fittest stations, formats and ways of working will survive, grow and reproduce constrained only by the technical and regulatory environment.
All this activity suggests that radio at 90, far from being a decrepit pensioner mumbling in a corner, is in fact a lusty infant with an awful lot of growing still to do.
I, for one, am looking forward to 2022's centenary celebrations with confidence. Bring it on.