When were you infected by Prog?

For me, it was Dream Theater. I discovered them at 14 after a friend mentioned their song Octavarium being 24 minutes long, which interested me in them. A while later, I borrowed Falling Into Infinity from another friend after I mentioned the band to him, and got hooked on that, and then I bought Octavarium a while later, and for ages that was the only prog I had. 

Oddly enough I was sleeping in a jar under the bed and had no awareness of ho old I was.

Hm... When was I infected by prog? Propably when I heard Ummagumma, Atom Heart Mother and Saucerful of Secrets

I really have to put this down to my older sister. In 1969 she bought a single by Australian Pop Star Russell Morris called The Real Thing. It was six and a half minutes of Psych Rock that made me sit up and listen. At the age of 9, I had been exposed to something that would guide my musical taste.
She then bought an EP by Led Zeppelin which had Whole Lotta Love on it. A year later, I had albums by Led Zepp, Deep Purple, Pink Floyd, King Crimson and Frank Zappa.
The next few years just got better and better. I added the obvious to the portfolio plus a few more obscure acts (Sebastian Hardie,Ayers Rock, Airlord). I took that natural side road into Fusion and have happily survived on a diet of both since.
Prog has opened up other horizons for me as well. It intoduced me to classical, folk, bluegrass, jazz and many other forms of music that make up my collection.
Most people, I know, think I am a dinosaur.
Well, long live the dinosaur. I say !   

I've always been into Rush, even as a kid hearing their hits on the radio all the time and then discovering what all they had to offer later on.  And I've always liked bands like Tool, Pink Floyd and Yes, not even realizing that they were prog, but I probably got heavily into progressive rock at the end of 2008 when a friend of mine told me about Porcupine Tree.  Soon after, I had to have anything and everything released by them and then this past summer, I discovered so many great prog bands that I probably bought close to 50 or so new prog albums to really immerse myself into this huge and diverse genre.  Some of the bands/projects that I'm really into are Porcupine Tree, Rush, Riverside, Osada Vida, Oceansize, The Pineapple Thief, Lunatic Soul, Indukti, Karnivool, Sky Architect, Pink Floyd, Yes, Tool and Transatlantic (although the vocals annoy me a wee bit in this band).

I'm still finding more great bands pretty much every week that I really enjoy!

Two albums started it off for me neither of which are classic prog per se: Autobahn by kraftwerk and A Night at the Opera by Queen. Combine the sounds of those two albums and there you have a lot of what I like about prog

I think when I got it from the toilet seat.

  Hello, I would have to say that I can remember several defining moment when I got infected. First one to come to mind is when a friend introduced me to ELP's Brain Salad Surgery. Oh my, what a masterpiece. I could not believe what an incredible/outrageous/beautiful/technically masterful piece of music I listened to or should I say experienced. We were  freshmen in high school at the time. A time when i consider to be an  incredible time of musical explosion. Thank God I was able to experience it ! 

It's fun to read all the different stories, and the different bands that got everyone infected! I bet you that, like myself, that first prog album that got you hooked is still one of your top favorites today...

As for myself, I guess I could say it was a two stage thing. Stage 1: when I was about 7 years old, me and a friend were flipping through my dad's record collection. We were drawn to one album because of the strange cover. We put the album on and we thought the music was somewhat funny. But we listened to it a few times actually. That album, strangely, was Triumvirat's Spartacus. I actually don't know to this day, why that album was in my father's collection, because he's a jazz man. He only had jazz albums, plus some popular oldies. That Triumvirat one was really out of place. But anyhow, without knowing it, I got infected by prog at that moment. But the bug lay dormant inside me for years after that.

I didn't even listen to much music after that. Only what my parents were listening to on the radio. When I was about 13, I started buying K-tel albums, so obviously pop was my thing. But that's when I really started listening to music. Shortly after, I enrolled into the Columbia House Records and Tapes Club, as it was named back then. My first 10 LP's I got from a friend's recommendation. At that time I started getting into hard-rock and metal (Def Leppard, Dokken, Ozzy Osbourne, Iron Maiden, to name a few, all of which I still like today), even though a Rush album was in the pack. Exit... Stage Left it was, but I didn't really listen to it.

Stage 2: I think I was 16, and I met someone who was a fan of Genesis. I knew Genesis, but the more pop 80's version of them. He had all their albums on tape. There was one album he had te re-buy, because it wasn't playing right anymore in his tape deck. I guess because he listened to it too often. So he gave that one to me to try in my deck, and he told me if it worked in my deck, I could keep it. I tried it, and it was playing fine in my dad's high quality tape player. Well, I was simply blown away by none other than Genesis' Foxtrot. At that precise moment, the bug woke up and infected my entire being.

In 1975, from a cheap, liquored-up floozie in Benidorm.