As a data point of one, I have noticed that since it is now more than 14 days since our second injection, I am definitely getting more careless. I have to actively work to oppose that pattern.
It's interesting to read about the response to the vaccine in the UK, as I live in the United States. I believe that an even higher percentage of people in the US will become complacent once they are vaccinated, but hopefully, there will be an end to all this soon.