I've kind of known who he was through researching some of the major teams, though I hadn't read any stories he's in.

Then. I'm reading the X-Men Essentials Vol. I and in one of the many potnetially reality-altering events, they get the Avengers on the video link.

Cut to an odd-looking Avenger wearing an antennae-simulating helmet, gasping, while his lady companion says "Just hold me, Hank!"

I immediately said "Goddamn, it's Ant-Man!" Ii really wanted to see him talk to some Ants, but oh well.