I am a relative latecomer to the OSR, and it means that I have missed a lot.
Blissful Ignorance
For decades, I enjoyed my gaming hobby in relative isolation. I have never been to a convention. I only read Dragon for a brief stretch from 1992-1995, I have only played a few sessions of Shadowrun Missions at my FLGS. And while I was pretty active on the official D&D forum for about three years, I didn't pay much mind to hobby news, and didn't stay with it when they migrated the servers in 2005.
In general I have been content to play Dungeons & Dragons, RIFTS, GURPS, Mage, and Shadowrun (with the odd game of HōL) with close friends and family, and be done with it. You can be very happy in this hobby ignoring what is going on behind the scenes.
When Dungeons & Dragons 4th Edition came out, WotC let slip on a podcast that two years worth of D&D3.5e products: the second round of Complete X, Races of X, the PHB II, and The Book of Nine Swords had all been just playtest material for 4th edition; they had used the culture of heavy rules chatter they'd fostered in the forums to turn them into a test lab, and had never really intended to support the material in those books after the edition rollover. I was incensed, and started looking for alternatives to D&D. I opted for Patfinder because it was familiar and compatible with my 3e collection.
I didn't discover the OSR until I had two small children, and couldn't get very much gaming in. I found that 5th edition Dungeons & Dragons was simply too cumbersome a system, and you couldn't actually accomplish a lot in the little time that I had for gaming. I wanted a game where you could get a lot more done in the time I had. And I remembered how quickly things moved back when I was a kid playing AD&D I'd remembered hearing about Labyrinth Lord, and started looking for mire info. And so it was just a few weeks before I started this blog that I got interested in the OSR. But this means that I have missed over a decade of cool stuff.