We've all berated the offenders, but it's rare that anyone admits to doing it.  Leaving a football match before the final whistle is very, very wrong though.  Mark Gilbey tried it once, here's what happened.

You should never leave a football match before the final whistle

With the possible exception of your wife going into labour or a chip pan fire, there really isn't a justifiable excuse for leaving a football match before the referee blows the final whistle.

Yep, just like sitting through your kid’s crappy school nativity play, no matter how turgid a performance you're witnessing, you simply have to stick it out.

And don’t you dare tell me you're one of those people who head for the exit a couple of minutes early to “beat the traffic”.

I have strong views about this, views that were relayed to me recently by my friends… shortly after I’d thrown a hissy fit like an eight-year-old girl and stormed out of London Road in the 62^nd minute after Brighton’s Ashley Barnes had scored a penalty to put them 3-0 up against my hometown club Peterborough a week last Saturday.

I was livid at every single one of the players, but now the anger has subsided I’ve realised I was a twat. A massive, massive twat.

There’s vague recollections of sitting alone near some goths in Cathedral Square, mumbling incoherently about Gary Johnson being sealed in a barrel and booted into the River Nene until I became too cold. I went to Waitrose and bought a lottery ticket, as if that was the answer to something (I didn’t win).

God knows what reception I’ll receive when Charlton come to visit this week, I’m half expecting to be tarred and feathered in the pub, not that I don’t deserve it.

Mainly I’m feeling a bit of a berk because I’ve been a dreadful supporter, not that I could have missed something at the game like Peterborough scoring four goals, or someone performing an outrageous piece of skill that’s been played to death on our television screens.

Yeah, I’d be pissed off, but that’s not the point. It makes no difference to me if Barry Fry had ran onto the pitch, dropped his pants and taken a huge dump in the centre circle.

Football is a form of entertainment of course, but it’s different, to say, going to the cinema and sitting through a film like The Social Network and hammering on the manager’s door demanding a refund because it was shit.

At the cinema you want, nay expect, to be entertained; you attend a football match to support the team first, to see them win second.

I might feel a little aggrieved at wasting a fiver and a couple of hours of my life at the cinema, but that’s it. When Peterborough lose, mine, and everyone around me, has his or her weekend ruined. And no, it isn't “just a game”. Peterborough United Football Club means something to me, it isn't just 90 minutes of my life on a Saturday afternoon.

Certainly we were due a spanking on recent form and Gus Poyet had Brighton playing some superb passing football in the 62 minutes I lasted at London Road, but we awful. I mean, truly abysmal.

No fight, no passion, no effort and don’t get me started on George Boyd’s sending off. It doesn’t excuse walking out though.

I wasn’t the only one. The Brighton following – a sizeable number by all accounts – gave sarcastic waves in the direction of the departing fans, while the ‘Boro faithful retorted with cries of “loyal supporters”.

They were aimed at me, I’m sure. I felt so embarrassed.

If possible, I think I’m worse than the “’scuse I, pardon I” brigade who look to beat the traffic, and cause inconvenience to everyone in their way as they beat a path to the exit. Some people will do this regardless of the score.

It beggars belief that someone would fork out all that money on a ticket just to miss the last couple of minutes. Even at 1-1 I’ll hear things like “see you next week, Steve”. Then “’scuse I, pardon I”. On the terraces this is mildly annoying, having to shuffle around in the critical moments of a match to allow them to pass; in an all-seater stadium it must be an absolute ball ache.

I’m a reserved individual, but when the final whistle sounds after a Posh victory I jump around like a loon on the terrace and shout at the top of my voice. I couldn’t do that in the town centre, not without the men in white coats coming to take me away, anyway.

Back to the game, and like a right twit, the first thing I did when I got home was switch on the television and see what the score was. I couldn’t tell you what emotions I was feeling when I discovered it was 3-0. Relieved? Pissed off?

What a twerp.

Sorry, Peterborough United. I’ll try to be a better a supporter this Saturday, honest.

You can read more from Mark at Four Four Two’s ‘Never Mind The Bolsheviks’ and be sure to follow him on Twitter @Mark_Gilbey