Miller Lite was invented in the late '60s, around the time baby boomers started to date, couple, marry and copulate (though not always in that order). As this new ad points out, this could hypothetically have led to your conception when your parents did it, probably under the influence.
It doesn't specifically say that. It more says that Lite beer let men keep their abs, which let them get dates, which led to marriages, which led to honeymoons, which led to you. But right when they're talking about your conception, you're seeing swingin' '70s-styled people toasting the camera with some frosty Lite beer.
So, maybe your mom was really shallow and picked you dad based on some choice fur-covered abs, or maybe she just got blitzed on Miller Lite and made poor choices. Either way, you're here now. And the new retro Lite can looks super cool, so crack open a cold one and celebrate!