(CNN) -- There's always something strange about bumping into an ex. Sometimes it can be satisfying -- perhaps they're looking a bit shabby, or have obviously fallen on hard times.
Maybe they've shacked up with someone new who, frankly, isn't much of a looker. Other times the reverse is true -- it's that day you're late for work and haven't had time to shower, or maybe the time you've had a drink too many and end up saying something embarrassing.
But most confusing of all is when, in spite of the knowledge of everything that went wrong in the past, that surge of mutual longing just wells right up again. Before you know it you're meeting for a drink and, well, you know the rest.
The problem for Chelsea, as for any serial daters, is that their exes are simply everywhere.
After rattling through 10 managers in 10 years, barely a month goes by without some awkward encounter to set the mind wondering what might have been.
Of course we all know what happened this summer. Fresh from ending a relationship with Rafael Benitez that, while doomed from the start, seemed to be developing into something a little more substantial, Chelsea were confronted with the newly single big love of their lives.
We've all seen it happen: two people who seemed so perfect together, but parted in haste, and suddenly they're both available.
The outcome is inevitable, and so it was at Stamford Bridge. Jose Mourinho moved all his stuff back in, started re-arranging the furniture and publicly re-affirming his undying love for the blue part of west London.
Now here we are, barely six weeks into the new season, and this time around it seems a little different.
Mourinho is as suave as ever, of course; witty press conference quips and a debonair touchline demeanor go a long way to making everything in the garden look rosy. But there's something oddly listless about his team.
To begin with, there's the question of the midfield. Juan Mata, the darling of fantasy football league managers everywhere, has been the lynchpin of so many good things about Chelsea since he signed; but from the moment Mourinho took charge the former Valencia maestro's place has looked in doubt.
Meanwhile, fellow attacking midfielders Oscar and Eden Hazard, while outrageously gifted, seem to pose more questions than answers.
How do they play together? Do they have the physical stature to impose themselves on more abrasive opponents?
Add in the return of another attacking midfielder, the exciting Kevin de Bruyne, loaned out successfully to Werder Bremen last term, along with the addition of buccaneering wide man Andre Schürrle, and there is a wealth of riches in the middle of the park.
Odd then that Mourinho chose to gazump one of Chelsea's most recent and perhaps bitter exes, Tottenham Hotspur boss Andre Villas Boas, and divert -- you guessed it -- yet another attacking midfielder, Willian, to Stamford Bridge.
How to fit any combination of these together into a usable whole, not least in the mayhem of England's rough and ready Premier League, is quite a conundrum. Right now Mourinho's first choice midfield is anyone's guess.
Then there's the front line. The football jury returned a verdict on Fernando Torres some time ago, and few would describe his time at Chelsea in anything more than tepid terms at best.
The fact that Mourinho has kept him on may owe more to an absence of realistic suitors than a desire to be the one who finally made things work with the Spaniard, but keep him he has.
Demba Ba has also struggled somewhat since joining from Newcastle, but while reports suggested he might have been off elsewhere, possibly to Arsenal, he has also stuck around.
Romelo Lukaku, another fantasy league favorite after a prolific season at West Bromwich Albion, seemed like the kind of rough diamond, with more than a little of Didier Drogba about his physique, that Mourinho could make shine.
But after an agonizing missed spot-kick at the end of 10-man Chelsea's spirited Super Cup final defeat against Bayern Munich, he will now be lining up in the blue shirt of Everton this season. With another former Chelsea man, Daniel Sturridge, setting Merseyside alight with his goals, it seems odd to let such potential go.
Competitive Premier League
Then there was the pursuit of Wayne Rooney.
Yes the Manchester United striker had frustrated former boss Alex Ferguson and needled his club's own fans more than once with his apparent desire to flee Old Trafford, and new manager David Moyes offered mixed messages about the forward's future.
But there always seemed something slightly implausible about the idea of the Red Devils letting Rooney join one of their title rivals.
And like Arsenal's myopic lust for Liverpool striker Luis Suarez, Chelsea's pursuit of Rooney seemed to become an obsession, while other possible targets such as Edinson Cavani and Falcao slipped through the Blues' net.
Finally, veteran striker Samuel Eto'o put pen to paper. While it is fair to say the 32 year old was unlikely to have been at the top of Mourinho's summer shopping list, he brings formidable experience and undoubted talent to the front.
Whether the flesh matches the mind and spirit will become clear in time, but this has not been the impact signing one would usually associate with a Chelsea summer.
None of this may have mattered much a few years ago, when the strength of this squad would probably have been enough to see the team through to a top two berth.
But the Premier League is quite a different place to the one Mourinho left. In fact it's fair to say it's a pretty different place to one of even a year ago.
Yes, Alex Ferguson's departure may yet have a negative impact on United, who haven't exactly handed Moyes the keys to the vault; but while Manchester City also have major changes to absorb, they look fiercely competitive on paper.
Elsewhere a resurgent Liverpool, a surprisingly effective Arsenal, and an intriguing Tottenham mean this year's race is a tough one to call.
Chelsea are in the mix, of that there is no doubt; but after their worst start to a Premier League campaign since owner Roman Abramovich took over it is difficult to cast them as favorites.
Ancelotti and Benitez
Perhaps the most interesting element in all of this is the performance of two other Chelsea exes.
Carlo Ancelotti, fresh from a triumphant season in France in which Paris Saint-Germain cruised to the Ligue 1 title and very nearly sprung a shock against Barcelona in the Champions League, has taken the helm at Real Madrid with steely assurance.
Three wins from four La Liga games and a crushing 6-1 Champions League victory over Galatasaray in Istanbul mark a team that looks well on track.
Ancelotti's departure from Chelsea was perhaps the most difficult to comprehend of all of this most capricious of clubs' break-ups. Given his record he looks more than capable of delivering the success Real fans crave.
Meanwhile, down in Italy's Campania region, Rafael Benitez's start at Napoli -- with a markedly changed team -- has been hugely impressive.
The Azzurri appear to have gelled immediately, as a series of dynamic and passionate performances fired them to the top of Serie A with a 100% start.
And that was before they dismantled a supremely talented Borussia Dortmund side in their first Champions League tie. Benitez -- the most unloved of former Chelsea partners -- looks to have found his perfect match in the shadow of Vesuvius.
As a bewildered looking Chelsea side left the field on Wednesday after their shock 2-1 home Champions League defeat to Basel, it was hard not to wonder if -- in the heat of the moment -- they had fallen back into the arms of the wrong ex.
That sensation was only compounded when the Portuguese accused his team of lacking "emotional maturity" in a post-match interview.
He was quick to shoulder the blame for the defeat in later exchanges, but there was a sense of alarm bells quietly ringing, especially with the news that Abramovich had joined his manager in the home dressing room for the post-match post-mortem.
After a fractious, draining and unfulfiling 2012-203 season with Real Madrid, which Mourinho himself admitted was the "worst of his career", was a rekindled romance with a past love, however heartfelt, simply chasing a passionate affair that had already run its course?
Early days it may be, but it will be interesting to see whether chapter two of this great romance evolves into another bitter divorce or a case of happily ever after.