So no, it wasn't your imagination. Many people who were fully vaccinated still got sick from the omicron variant -- but vaccine made it much less likely to cause death. Via the Washington Post:
While coronavirus shots still provided protection during the omicron wave, the shield of coverage they offered was weaker than during other surges, according to new data from the Centers for Disease Control and Prevention. The change resulted in much higher rates of infection, hospitalization and death for fully vaccinated adults and even for people who had received boosters.
The decline in protection continued a pattern driven by coronavirus vaccines’ reduced effectiveness over time, combined with the increasing contagiousness of the delta and omicron waves.
Before delta struck the United States in July, there were five to 10 cases of covid-19 for every 100,000 fully vaccinated adults each week, while the rate for unvaccinated people was 50 to 90 cases.
In the delta wave, unvaccinated people were five times as likely to get infected as vaccinated people. With omicron, that difference dropped to less than three times as likely.