The more things change, the more they stay the same.
Never has there been a better example of that than Manchester United under Sir Alex Ferguson.
For no matter how many players depart or whom is brought in to replace them, the philosophy remains intact - never give up, never surrender.
It is an attitude that can only have been passed down from dressing room to dressing room during Ferguson's near 25-year reign.
How else do you explain today's Community Shield result if most of the United players involved were mere children when the club's reputation for comebacks was first established?
Whereas Ferguson's youngsters had Paul Scholes or Gary Neville or Ryan Giggs to turn to in the past, today they did it all by themselves.
Sometimes, though, there is no substitute for battle-hardened experience and United may not have needed a comeback at all had it not been for their new goalkeeper.
Neville and Scholes both retired last season but it was the loss of Edwin van der Sar that left the biggest void.
And while it would be wrong to crucify a player on the evidence of just one performance, there was an alarming sense of deja vu about Davis de Gea's display.
None more so than for Ferguson, who could be forgiven for fearing a repeat of the nightmare he had trying to replace the great Peter Schmeichel.
Six years it took Ferguson to find someone up to the job, six long years which too often saw United play second fiddle to Chelsea and Arsenal.
De Gea could still be that man but he will have to be a very big man indeed to shrug off the errors which left the Barclays Premier League champions having to produce another one of their trademark fightbacks.
The young Spaniard stayed on his line when he should have come for the free-kick which led to City's opening goal, and he was even more rooted to the spot for an even more preventable second.
Until that point, United had been running rings around City, guilty of - if anything - over-playing.
Their opponents, meanwhile, were playing on the edge.
This fixture used to be called the Charity Shield but there was none of that on show from the FA Cup holders as Mario Balotelli butted heads with Nemanja Vidic, Edin Dzeko shoved Anderson, and Nigel de Jong clattered into Danny Welbeck.
At least Phil Dowd kept a sense of perspective, booking Micah Richards for a horrible tackle on Ashley Young that would have brought a red card in a league or cup game.
Against any other team, a 2-0 half-time lead for this expensively-assembled City side would have surely proved enough.
But it is never enough against United, who refused to change the way they were playing, despite Ferguson sending on even more youngsters at the break.
Chris Smalling kick-started the comeback before an early contender for goal of the season from Nani, who snared the stoppage-time winner thanks to the most uncharacteristic of errors from Vincent Kompany.
As Eric Cantona said last week, it is faith in youth that separates United from City.
What the Frenchman neglected to mention was that most of Ferguson's current crop youngsters have been recruited from elsewhere, rather than having been brought through the ranks.
But it seems not to have made a difference.
Despite this only being a 'friendly', United wanted it, wanted to send out a message to the 'noisy neighbours' who had humbled them at Wembley in April's FA Cup semi-final.
Both sets of fans had waited so long for such a day and now there have been two in the same year.
And if these are the kind of Community Shield matches we can expect from an all-Manchester affair then let us hope they both retain their respective trophies this season.