Harriet Walker: 'Shut up and get the party poppers ready!'

I went to a surprise party last weekend. The difference between a surprise party and a normal party is that, while you walk into the latter expecting to be greeted, welcomed and put at ease, at a surprise party, you're instantly chafed into doing some irksome task without anyone even saying hello, and instead of busying themselves pouring you a glass of wine, your host is frantically trying to pin up balloons in a position not immediately visible from the front door.

At a normal party you might expect to be ushered into a comfortable seat, but at a surprise party a red-faced German shouts out at you to get away from the window and take your standard-issue party hat off until the allotted time. In short, the difference between a surprise party and a normal party is that at one it's much better to be there at the beginning, and at the other it's better to be there at the end – but which way round you choose to interpret this really depends on your personality type, star sign and gluttony for punishment levels.

I've never had a surprise party, and I've never planned one. I don't think I want one, but I certainly wouldn't mind if someone threw me one. I hope, in fact, that this column doesn't preclude me from having one. I hope, too, with the preternatural angst that a surprise party instils even in people who don't know about them, that this column doesn't ruin one that's about to happen for anyone else, wherever they may be. I get the feeling that someone in Tonga is probably about to be scared out of their wits by a bellowing crowd of pals lurching round the corner with tooters and streamers any minute now.

As we prepared for my friend's surprise party, his girlfriend had to string out a tortuous excuse as to why the birthday boy was not allowed to do what he wanted on his birthday and instead had to leave the pub early and come home. This she achieved by pretending to lose some tickets to an event that had never existed, before fake-crying at something that had never upset her. (Imagine this level of meta-crisis at a normal party, where everyone is so drunk it would tie their brains in a knot and they'd have to unpick it with a pencil up one nostril.)

"I wish you'd just come home," she wailed down the phone in the corridor as the rest of us crouched in the sitting-room in our party hats, suitably far from the window but, crucially, not in eyeline from the front door either.

"Shall we turn the music down?" someone asked of the blaring 1980s rock that his girlfriend has supposedly put on to ease her fake tears. "SHHHHHHH!" shouted everyone else.

I got up to get a glass of wine (I know I promised not to mention it again, but crouching when you're still recovering from a broken leg isn't really an option without a glass of wine). "WHAT ARE YOU DOING? GET DOWN!" came the general chorus, even though the surprisee had not yet left the pub. It's a terrifying sight when social enthusiasm turns into military-level gung-ho; it's even more terrible when you know you have to plan to ruin someone's evening in order to get them to turn up at a thing that will – hopefully – make them happy.

"So what's the worst reaction we can expect?" someone asked to lift the mood and clear some of the latent panic that hung in the air alongside the precisely placed balloons and streamers.

"When I threw a surprise party for my girlfriend, she started crying," someone volunteered. "I knew someone who was so surprised they were sick in their hands," said another.

We began to worry that Ross would simply be so cross that his girlfriend – and by extension, all of his friends who were currently squatting behind the telly – had lied to him that the surprise might not be worth it. But then the phone rang. Mysteriously, my friend has her doorbell hooked up to her mobile, so you can be outside pressing the buzzer and she could let you into the building even if she were in Malibu, say, or Skegness. So the phone/doorbell rang, only to yield a couple of latecomers, who were suitably chastised for Almost Giving The Game Away. ("Get down, get your hat on, shut up and get your party popper ready.")

When Ross appeared three minutes later, all organising and order-following was forgotten and the place became a normal party, albeit one hosted by a girl who had pretended to cry to set it up and a boy who was trying not to as he thanked his guests for coming. It was a spectacle of human cheer and excitement at being, and simply having, friends, that was as overwhelming in its humility as our shout of "Surprise!" had been mumbled, out of sync, gargled and screeched.