What made the 1920s such an exciting period?

There were several factors. Talking pictures (movies). During Prohibition (no alcohol) the Mob came into effect and "bathtub gin" was one of the favorites and could be mixed with pure alcohol (many deaths ensued because of it.) It was party time at the night clubs (then called "speakeasies" where young women (no different than today) could party all night, do opium, cocaine, drink themselves sick yet rub shoulders with some of the Mob as well as movie actors. It was a time where the poor had a very hard life, but the ones that were lucky had the time of their life and free to do as they basically pleased.