Have you heard the one about Dragons' Den?
For me, the idea of standing in front of an audience of several hundred people, each of whom keenly expects you to make them laugh out loud, was pretty close to a nightmare. Not very different in fact, to standing in front of an audience only to remember that you haven't got any clothes on.
But sometimes it's good to dare yourself to do the unthinkable.
I've previously told friends that if I ever volunteer for any telethon duties alongside news presenters (dressing up in tights on Children in Need or whatever) they should shoot me.
But on this occasion, I was being offered the chance to collaborate with the properly funny Paul Merton. He was to be my coach. And I would be doing it alongside fellow Radio 4 presenters, Libby Purves, Peter White and Laurie Taylor.
With or without comic geniuses at our side, for the four of us amateurs engaging in this charity-supporting exercise, it seemed like a highly risky venture.
We would each have to write our own material (and what hard work that is). And at the end of it all, we'd perform at a comedy club in trendy Shoreditch.
Comic Relief of course couldn't lose. If we were funny, that would make people laugh. If we weren't funny? Well, that would probably make people laugh as well.
Now I can broadcast to an audience of several million people on the Today programme. I can talk about the day's news.
But on radio, believe it or not, we have notes and scripts. And while we might ad lib the odd wryly amusing asides, they come at the frequency of a suburban bus. About one every 90 minutes.
It's a big jump to get from there to a comedy club.
Paul Merton quickly broke some bad news to me: I needed to have jokes... not the occasional quip. I needed proper punchlines.
And I couldn't have notes.
Being funny, it turns out, is like being a bank. It's a confidence trick. As long as everyone believes in you, you are fine.
But as soon as you look like you're in trouble, you're really in trouble. The laughter will disappear as fast as money out the door of Northern Rock.
So Paul gave me the key tip. Get an early laugh to loosen everyone up.
The hardest part is thinking of the funny lines. It's much harder work than you'd imagine. You inevitably end up being a bit egotistical and talking about yourself rather a lot.
As a (former) economics journalist, I could do a little bit on economics. But my efforts were a bit feeble. (What's Alistair Darling's biggest problem? Unlike other chancellors, he can't blame his predecessor for everything.)
Unfortunately, in economics there is more to cry about than laugh about at the moment.
But as the presenter of the programme Dragons' Den, I thought I must be able to get a joke or two out of that. After all, this is the country that invented the hovercraft, the jet engine and the antibiotic.
On Dragons Den we've continued the tradition with the one handed glove (beaten to a patent by a one-handed mitten); and the fruit blender with broadband connection.
OK, I had to employ some comic timing and extreme exaggeration... but I knew I could make these ideas sound funny.
Well, the big night where all our work was to be tested came along this week.
The closer it got, the more nervous I became. You see, when comedy goes wrong, it goes far more wrong than the other arts. If we just had to sing or dance, the worst that could happen is that we do it badly for five minutes and then walk off to polite applause.
Comedy is a participation sport though... you need the audience to react continually. You don't wait until you've finished to see whether they liked you or not.
And in the run up to the event, it's amazing how unfunny I felt. People would talk to me encouragingly, undoubtedly expecting a quick and witty response. All they got was a glum looking wreck.
In the event though, it went well.
The crowd laughed in all the right places... and even in some of the wrong ones. They even giggled a bit at the comment about Alistair Darling.
I left the stage feeling elated, and listened to my three colleagues who were all more ambitious and funny than me (a bit annoying that, as we have to raise money for charity somehow and we now face a vote by Radio 4 listeners to choose the best of us).
But none of that matters.
Comic Relief has got some free comedy, and for those of us performing it went ok. What a relief.
Performing their first ever stand up gig alongside Evan will be Libby Purves, Laurie Taylor and Peter White, with their mentors, Milton Jones, Shappi Khorsandi and Josie Long.
Comic Relief - Stand up With The Stars can be heard on Sunday 1st and Sunday 8th March at 1.30pm on BBC Radio 4. Listeners can vote for their favourite performance after the first show and proceeds will go to Comic Relief. The winner will be announced on The Now Show on Red Nose Day (Friday 13th March) at 6.30pm on BBC Radio 4.
(Evan's one-liner on the Today programme:
How do you tell when a politician is telling the truth on the Today programme? Nobody knows - it's never been tried.)