In the early days of Netflix streaming, not so long after it graduated from mailbox DVD delivery (if you remember that, you old fossil, you), its catalog was largely a sparse and obscure hodgepodge of films and TV series either long out of date or raked in from somewhere English-speaking but without American mass-market licensing fees. I guess that’s how my wife and I found “Extras,” British comedian Ricky Gervais’s bargain-basement BBC follow-up series to “The Office,” about a pair of failed actors in their 40s doing background work, their dreams of fame withered and limp. Filled with A-list cameos — Orlando Bloom, Samuel L. Jackson, Sir Ian McKellen, Kate Winslet, all playing themselves against Gervais and costar Ashley Jensen’s pathetic overtures — “Extras” is backstage comedy played as theater of the absurd. Just one season was available on Netflix when we watched it all those years ago, which was just as well given its squirm-inducing level of humiliation comedy. Just last week, newly shut in, we found there was another whole season and dived in. Things had changed for Gervais’s Andy, having successfully pitched a sitcom to the BBC, though it wasn’t going quite as he’d hoped. Moaning about the network’s dumbing-down of his artistic vision in a VIP lounge to, of all people, David Bowie, Andy inspires a spontaneous song. I’ll say no more, beyond: It’s as close to laughter-asphyxiation as I’ve ever come.