The opening sequence of “Jackass Forever” is one you’ll never forget. It’s a piece of filmmaking so bold, so audacious and so unbelievably, sublimely stupid that it will no doubt etch itself on your brain for years to come. I don’t dare describe it in print, because everyone deserves to discover it for themselves, but also because this publication wouldn’t be able to print the details. Let’s just say it’s “Godzilla”-inspired, with a uniquely “Jackass” twist. “Sublimely stupid” is what the “Jackass” crew does best, and their formula (thankfully) hasn’t wavered since the prank/stunt reality come…