I've been shooting BB guns at soda cans since I was three. I was so small that I had to put the stock over my shoulder and shoot it like a Bazooka. I don't ever remember learning gun safety or how to shoot rifles accurately because it was something I was taught from birth.
Despite this Dad wasn't (and isn't) really a gun guy (eight kids may have something to do with it (I'm the eldest)). He used to be big into firearms, but kinnda' lost interest once he got married. I always wanted him to take me hunting, he had hunted when he was younger, but didn't want to deal with the hassle of it all. I started getting to shoot his 10/22 at the family land when I was 12-13, mostly doing target shooting.
One 4th of July some friends of friends brought a bunch of guns down to the land, and being 15 and not yet having shot anything bigger than a .22 I had a blast. I got to shoot a Glock in 10mm, a 1911, a 12 gauge PGO (OUCH! (though admittedly I held it wrong)), a SKS on a bipod, and a couple pocket pistols in .32 and .38. Apart from being sweeped by a disgruntled wife who didn't like the way a gun shot it was a good day. Ever since then I started saving for a rifle. When the Sandy Hook shooting occurred my dad told me to find one quick (my birthday was a month away and he said he'd make up whatever I was lacking as far as funds go). I had already decided that I wanted an AKM. So I got on ArmsList and was able to arrange to buy one about a week before prices went through the roof.
Since then my interest, which was a bit slow coming to fruition, has expanded. I have bought a bow because I couldn't stand to wait for November to go hunting, and I now own several more firearms. At this point in time I'm eagerly waiting for my 18th B-Day at which point I'll be able to Open Carry.
To answer the original question. I'd known that there were people who didn't like guns, but didn't know that there was really an 'anti-gun' camp until Sandy Hook. Of course being Home Schooled may have had something to do with that
At any rate myself, my brothers, and the (Home Schooled) Neighbor always ran around all morning with toy guns, played "Goldeneye 007" on the N64 and were generally did stuff a liberal would have a heart attack at. I was allowed to watch any movie as long as the only "bad" stuff in it was violence, sooo.... yea...