Because you just saw this video online of a bunch of people on a bus that looked super fun, book yourself a seat on BrewTruc, an honest-to-God bar housed inside a 40ft chrome-bumpered school bus outfitted with 12 custom beer taps (six inside, six out) and stocking 93 gallons of beer, or what Rip Torn's stomach calls "Thirsty Thursday, bitches".
Licensed sorta like a limo (meaning you can drink while it's moving, or trying to win over hooker-turned-classy-lady Julia Roberts), its leather-cushioned walnut benches'll sit 28 whilst they enjoy Belgians, micros, and not-otherwise-sold-to-the-public beers from SF garage-breweries like Poplar Brewing Co, Pine Street Brewery, and Muddy Puddle, a Mill Valley nanobrewery run out of a 1920s bungalow by a dude who helped brew the original Big Daddy IPA.
As most of you were already sold by the Bangbus allusion (whhhhich is what was going on up there, thank you), you'll be happy to learn that you can access this puppy in one of three ways: 1) claim your seat for an existing excursion on their schedule (food truck gatherings in Upper Haight, sunset-watching by the Golden Gate, etc.), 2) set your own destination (CROCKER AMAZON!!) when booking a private drink-a-thon with 20 of your friends, or 3) meet them at one of their charity beer gardens, where they'll post up at parking lots across the city and sling 90% of their profits to worthy causes.
But wait, there's more: they've also got plans to aid your pre-concert imbibing regime by making special trips to Golden Gate Park during Hardly Strictly and Outside Lands, meaning unlike the actresses in that vid, you can cop a bus ride without having to entertain outside hands.