Ricky Gervais is an actor, writer, and director. He is brave. I am a standup. I am not brave. I only ever did one brave thing. In 2005, I agreed, while drunk, to jump off the tallest structure in New Zealand. New Zealanders' high living standards mean they are driven to create artificial jeopardy, usually involving jumping off things, stamping their bare feet on hard mud, or eating deceptively hot pies from roadside vendors.

Illustration by David Foldvari.

Visitors to the Auckland Sky Tower can freefall from 650 feet at 60 miles an hour. A brake kicks in for the last 10 feet, so you realise what it would be like to die, but don't. I panicked, and started telling the men that I didn't want to do it, but I was already on a ledge high over the city so they just snapped the clips and pushed me off. As I fell I realised that one day I would be dead, that the world would continue without me, and that I was nothing. I wish I'd just eaten the pies.

Members of the public are always telling standups that we must be very brave. Some of you who have told me this are a fireman, a community policewoman, and a mercenary who chases Somalian pirates. The fireman is half right, I suppose. Once extinguished, a fire is done. However, an extinguished heckler can later go on an internet forum and say I'm shit and that he hopes various women I know are raped.

You say standups must be brave because anything can happen in a live comedy show, and that's true, but only within certain parameters. The laws of physics will remain constant. Gravity will not reverse. Giant moths will not swoop down and carry the comedian away. And while Eddie Izzard always dresses as a woman before performing, the average comedian is unlikely to change gender mid-gag, like a west African frog.

I have, however, seen some of you physically attack standups onstage. And I even saw one of you wave a gun during the young David Baddiel's act in a Montreal club in 1997. The gunwoman's defence, namely that she had been sent back from the future to avert a catastrophic event called "Baddielageddon", was dismissed as fantasy by the arresting officers, perhaps with indecent haste.

A confusion seems to exist in your minds that a comedian is somehow validated by doing material that you perceive as being "brave". Lenny Bruce was brave to challenge orthodoxies in front of audiences peppered with FBI agents aiming to arrest him. Chubby Roy Brown is not brave to sing a pro-golliwog song in front of loads of people who, from the YouTube clip, seem to be all disproportionately enthusiastic about golliwogs. Perhaps it was a private booking for a golliwog enthusiasts' group?

But as ideas of what's acceptable change, it can be difficult for comedians to know if, at any particular point in time, we are being brave and clever, or offensive and stupid. For example, in 2008, the standup comedian Russell Brand was censured by the Yorkshire Michael Parkinson, having joked to an old Mexican grandad about having sex with a goth. Back in February 1977, the letters page of the Radio Times carried a letter from a viewer criticising Michael Parkinson for laughing along to Bernard Manning's "racist" jokes on his TV chat show.

Was Russell Brand "brave" to have joshed the old man about the goth sex? Was Manning "brave" to be racist in the 70s, even though racism was largely thought of as ace until UB40's first album, Signing Off, discredited it? And would Michael Parkinson have thought it was OK for Russell Brand to do the old Mexican grandad goth sex prank if he had used the Baddielogeddon portal to go back 40 years in time and do it in a comedy Pakistani voice?

Today, furious internet commentators, and cab drivers who vaguely recognise me, think the bravery of a comedian is measured by their willingness to tackle the hot potato of Islam. (Yes, I know it is forbidden in the Koran to warm a potato, even accidentally. This is merely a figure of speech. I meant nothing by it. I was not trying to be brave.) Here is a selection of almost three unsolicited emails the BBC received during my last TV outing, from people desperate to see Muslims mocked, both implying my lack of bravery.

"Dear BBC, I enjoyed Stewart Lee's making fun of Chris Moyles on TV last night. I look forward to him mocking the Prophet Mohammed in the same way next week, or wouldn't that be 'politically correct'?" And, "Dear BBC, I enjoyed watching Stewart Lee making jokes about crisps last night. But I doubt we will be seeing him having a go at any Muslim snacks in the near future. It appears there's one law for crisps and quite another for spicy bombay mix." These two emails, which were both sent by Norris McWhirter, are not real. But there are many like them that are.

Islam is not the comedy taboo the fictional Norris McWhirter imagines it to be. Many standups, and often those of an Islamic background, do make informed jokes about Muslims. So where can the would-be brave comedian go to prove his bravery? Well, just as he did with The Office nearly 30 years ago, once again, the self-styled "little fat bloke" Ricky Gervais has shown us all the way.

On his blog last month, Gervais claimed to be working on a sitcom about a "lovely little feller" called Derek, and linked to a YouTube clip of himself as Derek Noakes, a 38-year-old man whose non-specific mental condition, with some superficial similarities to Down's syndrome, and vulnerability to sexual abuse, are the source of some typically opaque Gervaisian irony. Morgana Robinson's eponymous C4 series featured Gilbert, a foolish "special needs" boy and his disabled friends, but it looks as if the glamorous comedienne's bravery is about to be eclipsed by Gervais'.

Gervais's fans have already praised his brave reclamation of the word "mong" last month, but his decision to make comedy about the mentally handicapped more explicitly may be the heroic multimillionaire actor-writer-director's bravest yet. To return to our opening metaphor, if "mong" is a hot pie, Derek Noakes is the full Sky Tower.

It would, doubtless, be brave for Gervais to pursue his Derek Noakes sitcom. It would be braver for him to staple his penis to a wolf. And braver still for him to run into a threshing machine, pushing children in wheelchairs in before him. But watching Gervais's Derek Noakes on YouTube, I imagined feral children trailing real Dereks around supermarkets, chanting "Derek Derek", as they doubtless would were the series to be made, and wondered if, sometimes, discretion is not the better part of valour.

Carpet Remnant World is at Leicester Square Theatre from 15 Nov and tours throughout the UK in Spring 2012. See stewartlee.co.uk