I think many of our fans are fairly deluded (myself included). I don't think we have ever been the dominant force in English football. That includes 68 to 73. Maybe if we'd done the double in 68 or won championship in 72 you could make a case. But as the record books stand - the 1968 championship was a flash in the pan.
I get the impression from historical sources, that City could have been a dominant powerhouse in the 1930's. Alas, Herbert Chapman had turfed up at Arsenal, and they made that decade theirs.
Most clubs have history. I think City may be amongst the clubs with the biggest gap, historically, between expectation and actual achievement. That would therefore make us amongst the most deluded? My point is, City fans have always regarded City as a top club - when by a large, we have not been.
Of course, The Toon army takes delusion to a whole different level. Their astonishing reality gap between imagined history and fact challenges the known laws of physics. But I think we run them a close second. Spuds are almost as bad as us - if only they didn't have such a record of overachieving in cups. It's a long way back to 1961 - but winning the double when it meant something still matters.
Villa and Everton have far more successful histories than us. Even Leeds (washes out mouth).
The lesson of Manchester City is that if you maintain your delusion no matter how outlandish and in the face of all the evidence to the contrary, something may happen to shift reality in the direction of your delusion. Sadly for the Toon, the chances of this happening twice in any universe are extremely low.