Every man and woman over fifty ought to read Seventeen . . . No mature person who reads this novel will ever seriously regret his lost youth or wish he were young again....

-- William Lyon Phelps

 Among other things, it would mean thinking the way Our Hero does when he "can't" go to the big dance because he's  no longer able to swipe his father's tux and pass it off as his own:

It did not once enter his mind that he could go to the dance in his "best suit," or that possibly the other young people at the party would be too busy with their own affairs to notice particularly what he wore. It was the unquestionable and granite fact, to his mind, that the whole derisive World would know the truth about his earlier appearances in his father's clothes. And that was a form of ruin not to be faced.