It has happened on numerous occasions, regardless of our form, the opposition and the division. However, it's probably something fans of any club could say - we only remember it happening with our club because we don't pay a great deal of attention when it happens to someone else. Mind you, Celtic were on a bit of a downer when we last played them in the league - and we lost 7-0. Then, in even more typical Saints style, we beat them in the cup a week later!
Of course, a bad run of form for Celtic isn't necessarily a disaster for anyone else. They are, after all, just a point off the top of the league and unbeaten at home all season. OK, they aren't playing particularly well but, for the most part, they are getting results. Despite this, I know many Celtic fans who aren't happy with what's happening and aren't too bothered about the club any more - although that will mysteriously change when they suddenly get a few results under their belts. These are the same people who slated Gordon Strachan for the last few years, even though they were pretty successful. No doubt they'd be baying for blood if he was doing what the rather more Celtic-minded Tony Mowbray was doing.
Celtic have plenty of people we'll need to be wary of, and not just the referee. Scott McDonald is Celtic's equivalent of Kris Boyd - he scores goals but also gets plenty of stick. He's a fine player in the SPL and will fancy his chances of bagging a few tomorrow. Aiden McGeady and Shaun Maloney are quite handy when they aren't falling over, both capable of providing and scoring goals in equal measure.
When Mowbray arrived, there were hopes from Celtic fans that they'd start playing the mythical "Celtic Way", whatever that is. Their performances haven't been great, but there have certainly been flashes of brilliance and when the team clicks they are a devastating sight. McDonald, McGeady, Maloney and the trickery of Niall McGinn and Paddy McCourt will prove plenty for our back four to deal with - and that's before you mention their aerial threat from set pieces in the shape of Glenn Loovens, Gary Caldwell and Stephen McManus.
As this is an away game against one of the Old Firm, you can be rest assured we'll go with Billy Mehmet on his own up front and Garry Brady in midfield. You can also be fairly sure we'll probably lose an early goal! The 4-5-1 doesn't seem to work, especially as we play five central players in the midfield. If we do insist on playing it, I would like to see Mehmet played on the right wing with Michael Higdon or Craig Dargo - now just about fit - up front. Mehmet seems to drift out wide a lot of the time anyway so it would be interesting to see if he can be effective when he starts a game out there.
John Potter will be back in the squad after overcoming an infection, although last time he was at Parkhead he scored an own goal! I'd be inclined to leave him on the bench, even if he is captain, as Chris Innes and Lee Mair looked reasonably solid against Hibs last week. Chris Smith, Steven Robb and Mo Camara are all back in training too, although probably won't be involved, while Tom Brighton is obviously out for the long term.
It's the best part of 20 years since we last beat Celtic in the league, with Guni Torfason, George Shaw and Paul Lambert scoring in Glasgow's East End for a win now immortalised in song. Can some of our current crop have a tune dedicated to them after tomorrow?