Aiming for a story set about 1930, I've been reading a lot about the Prohibition Period in America, and I would have to say that, yes, people knew that times were good and that they had a better shot at a good life than in most eras. Outside the range of the Volstead Act, the positive mood was more definite, unless you were someplace like Berlin or Moscow.

A peppy little number sung by Rudy Vallée, "The One That I Love," expresses the general optimism of even the lower classes: "where the money's from, I don't know, still, I'm buying a bungalow." Most people expected to have a pretty okay life, unless they were in desperate circumstances. They would have a little place of their own, with someone they loved, raise a couple of kids, have a good time. The economy was booming, technology was zooming (radios with speakers! dirigibles over the North Pole! radium anything and everything!), no wars were looming as everyone recovered from the Big One. After an initial post-war recession, the economy went into overdrive. You could buy anything on time payments, and financing was easy.

One of the reasons for all those tempests in teapots is that there often wasn't more important stuff for newspapers to fuss about, so flag-pole sitters, cross-country backwards walkers, and organized crime got front pages. I'm getting a lot of research mileage out of Popular Science Monthly both ads and articles. There is sooo much on radio in all its permutations, and on aeronautics. Everything else takes a back seat to them. The articles on science in crime detection show that there was a lot, yeah, but I bet a check of the FBI statistics shows them all much lower. The one on rum-running shows that most alcohol was not smuggled, but produced inside the country, either illegally or by high-jacking legal runs. The 1920s volumes are much jauntier and less practical than those of the 1930s: lots of "witty" cracks on tropes of the period, more "lookit this crazy thing!" rather than "here's how to get by" and "seriously, this is the future."

More children than ever got to attend high school, and a higher percentage graduated. An increasing percentage went on to college, not just from the upper classes or from the genius pool, but fairly ordinary but intelligent middle class kids might aspire with reason to a sheepskin -- and to meeting and hanging around with the other groups. The inventive genius who did not have a STEM degree began to vanish. With this came the whole "Betty Co-Ed"/college fight song/coonskin coat and ukulele way of life, including the hip flask. Prohibition brought on skyrocketing rates of drinking by college students and high schoolers, too. (Alternative reason: a change in who was a college student, and why?)

People acknowledged the imperfection of the world and society, but many felt it was nothing that science, technology, and good will couldn't lick, especially with some time to change people's attitudes. A much smaller faction were the world-weary WW1 survivors, cynics to whom everything was doomed so you might as well enjoy what you could while you could. Consider the same divergence at almost any time of the 20th C, between the decadent intellectual and the folks on Main Street.

The average person in the Anglophone world -- not famous, not important, not biographied -- seems to have expected this decade to be good and life to get better.

SOURCES:

Frederick Lewis Allen. Only Yesterday: An Informal History of the 1920's (1931)

Barrington Boardman. Flappers, Bootleggers, "Typhoid Mary" & The Bomb: An Anecdotal History of the United States from 1923-1945 (1988)

Edward Behr. Prohibition: The Thirteen Years that Changed America. (1996, 2011)

Hildegarde Dolson. We Shook the Family Tree (1946)

Orville O. Hiestand. See America First (1920)

Rian James. Dining in New York (1930)

Ruth McKenney. My Sister Eileen (1938)

Daniel Okrent. Last Call: The Rise and Fall of Prohibition (2010)

Michael E. Parrish. Anxious Decades: America in Prosperity and Depression, 1920-1941 (1992)

Emily Post. Etiquette (1922)

Jon Savage. Teenage: The Prehistory of Youth Culture 1875-1945 (2007)

Kelly Schrum. Some Wore Bobby Sox: The Emergence of Teenage Girls' Culture, 1920-1945 (2004)

Charles W. Stein. American Vaudeville as Seen by Its Contemporaries (1984)

Wallace Thurman. Negro Life in New York's Harlem: A Lively Picture of a Popular and Interesting Section (1927)

Rudy Vallée. Let the Chips Fall . . . (1975)

The Editors of Time-Life Books. This Fabulous Century v. III, 1920-1930 (1969)

1922 Montgomery Ward & Co., Catalogue No. 97 Fall & Winter 1922-1923

Popular Science Monthly, 1920-1934